[gentoo-user] grub and what happens exactly when booting.

[gentoo-user] grub and what happens exactly when booting.

[Dale]

OK.  The Chief Idiot is going to experiment some.  You ALL know what 
this means right?  Yep, I'm about to really make a mess of things so 
here comes some questions.  This is a result of the /usr and udev crap.  
So, go to -dev and blame them, not me.  ;-)

OK.  I have three drives in my rig.  One is for data files, mounted on 
/data ironically, and has nothing to do with the OS.  So, for that 
reason I'm going to leave it out of this.  So, I now have two drives in 
my rig that are about to be OS related.  sda is a 160Gb and sdb is a 
250Gb.  I'm going to leave the first one, sda, as is and will use sdb 
for testing.  Before I start, I want to sort of get my brain wrapped 
back around this.  It has been a LONG time since I dual booted Linux and 
that was only for a month or so.  I have grub installed on the MBR of 
sda.  My boot partition is on sda1 like most likely 99% of the rest of 
you and it will stay there even after all this is done.  I got /boot 
from the old handbook days.  When I put my new install on sdb, with this 
new initramfs thingy and quite possibly LVM, do I leave grub on sda's 
MBR and just point to sdb for the kernel and init thingy and all will be 
well?

If this all works out, I will be moving everything from sdb to sda 
anyway.  My plan is to get them both bootable, then use one to copy to 
another after I have learned a bit about this mess.  I haven't got that 
far yet but wanting to figure this init thingy out before I'm forced to 
which will only make it taste even worse.

What I am reading so far:

http://en.gentoo-wiki.com/wiki/Initramfs

I did a google search and found some others boot this is more Gentoo 
oriented.  So, anything wrong with this as a guide?  Pointers to others 
if they are better would be great.

Here starts a learning process.  It could get bumpy.  lol

Dale

:-)  :-)

Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

Dale wrote:
> << SNIP >>
> What I am reading so far:
>
> http://en.gentoo-wiki.com/wiki/Initramfs
>
> I did a google search and found some others boot this is more Gentoo 
> oriented.  So, anything wrong with this as a guide?  Pointers to 
> others if they are better would be great.
>
> Here starts a learning process.  It could get bumpy.  lol
>
> Dale
>
> :-)  :-)
>

Oops, typo up there.  Should read "I did a google search and found some 
others *but* this is more Gentoo oriented."  Hey, I got the first and 
last right.  lol

While I am at this.  I just noticed something else.  I think this 
changed after the openrc upgrade.

root@fireball / # mount
rootfs on / type rootfs (rw)
/dev/root on / type reiserfs (rw,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
rc-svcdir on /lib64/rc/init.d type tmpfs 
(rw,nosuid,nodev,noexec,relatime,size=1024k,mode=755)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime)
udev on /dev type tmpfs (rw,nosuid,relatime,size=10240k,mode=755)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620)
shm on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime)
/dev/sda1 on /boot type ext2 (rw)
/dev/sda8 on /var type ext3 (rw,commit=0)
/dev/sda6 on /usr/portage type ext3 (rw,commit=0)
/dev/sda7 on /home type reiserfs (rw)
/dev/sdc1 on /data type ext4 (rw,commit=0)
usbfs on /proc/bus/usb type usbfs (rw,noexec,nosuid,devmode=0664,devgid=85)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc 
(rw,noexec,nosuid,nodev)
tmpfs on /var/tmp/portage type tmpfs (rw,noatime)
root@fireball / #

Now usually when I boot into a dual OS, I go to a console and type in 
mount and make certain of what drive / is mounted too.  Example for 
this, if mounted to sda* then it is my main OS and if mounted to sdb* 
then it is my test install.  How does one decipher that up there?  Heck, 
root could be mounted on anything right now.  I'm not going to remove 
any partitions right now.  I could be running off sdb and not even know 
it.  o_O

Dale

:-)  :-)

Re: [gentoo-user] grub and what happens exactly when booting.

[Pandu Poluan]

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On Sep 16, 2011 9:11 AM, "Dale" <rdalek1967@gmail.com> wrote:
>
> Dale wrote:
>>
>> << SNIP >>
>>
>> What I am reading so far:
>>
>> http://en.gentoo-wiki.com/wiki/Initramfs
>>
>> I did a google search and found some others boot this is more Gentoo
oriented.  So, anything wrong with this as a guide?  Pointers to others if
they are better would be great.
>>
>> Here starts a learning process.  It could get bumpy.  lol
>>
>> Dale
>>
>> :-)  :-)
>>
>
> Oops, typo up there.  Should read "I did a google search and found some
others *but* this is more Gentoo oriented."  Hey, I got the first and last
right.  lol
>
> While I am at this.  I just noticed something else.  I think this changed
after the openrc upgrade.
>
> root@fireball / # mount
> rootfs on / type rootfs (rw)
> /dev/root on / type reiserfs (rw,relatime)
> proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
> rc-svcdir on /lib64/rc/init.d type tmpfs
(rw,nosuid,nodev,noexec,relatime,size=1024k,mode=755)
> sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
> debugfs on /sys/kernel/debug type debugfs
(rw,nosuid,nodev,noexec,relatime)
> udev on /dev type tmpfs (rw,nosuid,relatime,size=10240k,mode=755)
> fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
> devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620)
> shm on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime)
> /dev/sda1 on /boot type ext2 (rw)
> /dev/sda8 on /var type ext3 (rw,commit=0)
> /dev/sda6 on /usr/portage type ext3 (rw,commit=0)
> /dev/sda7 on /home type reiserfs (rw)
> /dev/sdc1 on /data type ext4 (rw,commit=0)
> usbfs on /proc/bus/usb type usbfs
(rw,noexec,nosuid,devmode=0664,devgid=85)
> binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc
(rw,noexec,nosuid,nodev)
> tmpfs on /var/tmp/portage type tmpfs (rw,noatime)
> root@fireball / #
>
> Now usually when I boot into a dual OS, I go to a console and type in
mount and make certain of what drive / is mounted too.  Example for this, if
mounted to sda* then it is my main OS and if mounted to sdb* then it is my
test install.  How does one decipher that up there?  Heck, root could be
mounted on anything right now.  I'm not going to remove any partitions right
now.  I could be running off sdb and not even know it.  o_O
>

Try 'realname /dev/root'. Or realpath, I forgot which exactly.

Heck, just do 'ls -la /dev/root' :-)

It's a symlink to the actual dev

Rgds,

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Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

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Pandu Poluan wrote:
>
>
> On Sep 16, 2011 9:11 AM, "Dale" <rdalek1967@gmail.com 
> <mailto:rdalek1967@gmail.com>> wrote:
> >
>
> > Now usually when I boot into a dual OS, I go to a console and type 
> in mount and make certain of what drive / is mounted too.  Example for 
> this, if mounted to sda* then it is my main OS and if mounted to sdb* 
> then it is my test install.  How does one decipher that up there? 
>  Heck, root could be mounted on anything right now.  I'm not going to 
> remove any partitions right now.  I could be running off sdb and not 
> even know it.  o_O
> >
>
> Try 'realname /dev/root'. Or realpath, I forgot which exactly.
>
> Heck, just do 'ls -la /dev/root' :-)
>
> It's a symlink to the actual dev
>
> Rgds,
>

Dead on the mark:

root@fireball / # realpath /dev/root
/dev/sda3
root@fireball / # ls -la /dev/root
lrwxrwxrwx 1 root root 4 Sep  2 09:11 /dev/root -> sda3
root@fireball / #

Thanks.  It is sda.  Whew !!

Dale

:-)  :-)

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Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Thu, 15 Sep 2011 20:49:02 -0500
Dale <rdalek1967@gmail.com> wrote:

> OK.  The Chief Idiot is going to experiment some.  You ALL know what 
> this means right?  Yep, I'm about to really make a mess of things so 
> here comes some questions.  This is a result of the /usr and udev
> crap. So, go to -dev and blame them, not me.  ;-)

Uh-oh!  :-)

> 
> OK.  I have three drives in my rig.  One is for data files, mounted
> on /data ironically, and has nothing to do with the OS.  So, for that 
> reason I'm going to leave it out of this.  So, I now have two drives
> in my rig that are about to be OS related.  sda is a 160Gb and sdb is
> a 250Gb.  I'm going to leave the first one, sda, as is and will use
> sdb for testing.  Before I start, I want to sort of get my brain
> wrapped back around this.  It has been a LONG time since I dual
> booted Linux and that was only for a month or so.  I have grub
> installed on the MBR of sda.  My boot partition is on sda1 like most
> likely 99% of the rest of you and it will stay there even after all
> this is done.  I got /boot from the old handbook days.  When I put my
> new install on sdb, with this new initramfs thingy and quite possibly
> LVM, do I leave grub on sda's MBR and just point to sdb for the
> kernel and init thingy and all will be well?

The basic idea is you set the boot drive in the bios and which runs grub
from that drive's mbr. When you installed that grub you hard-coded it
to know where to find it's grub.conf.

You can use the existing grub and it's config files just fine. Add a
new entry for your new stuff on sdb - grub will reference that drive as
(hd1) in grub.conf - and configure the root, kernel and initrd
settings appropriately.

If I were you I'd install grub to the mbr on sdb as well. If you happen
to switch sda and sdb around, you'll still have code to boot from on
the new first drive and not need to change the boot drive settings in
the bios. It's not a necessity, just a convenience.



> 
> If this all works out, I will be moving everything from sdb to sda 
> anyway.  My plan is to get them both bootable, then use one to copy
> to another after I have learned a bit about this mess.  I haven't got
> that far yet but wanting to figure this init thingy out before I'm
> forced to which will only make it taste even worse.
> 
> What I am reading so far:
> 
> http://en.gentoo-wiki.com/wiki/Initramfs
> 
> I did a google search and found some others boot this is more Gentoo 
> oriented.  So, anything wrong with this as a guide?  Pointers to
> others if they are better would be great.
> 
> Here starts a learning process.  It could get bumpy.  lol
> 
> Dale
> 
> :-)  :-)
> 



-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

Alan McKinnon wrote:
> The basic idea is you set the boot drive in the bios and which runs grub
> from that drive's mbr. When you installed that grub you hard-coded it
> to know where to find it's grub.conf.
>
> You can use the existing grub and it's config files just fine. Add a
> new entry for your new stuff on sdb - grub will reference that drive as
> (hd1) in grub.conf - and configure the root, kernel and initrd
> settings appropriately.
>
> If I were you I'd install grub to the mbr on sdb as well. If you happen
> to switch sda and sdb around, you'll still have code to boot from on
> the new first drive and not need to change the boot drive settings in
> the bios. It's not a necessity, just a convenience.
>
>

That's what I was thinking.  Now that I got that straight in my head.  
Moooooving on.

I was wanting to play with reiserfs4.  Where in the heck is the 
command?  I have this:

root@fireball / # mk << tab twice >>
mk_cmds           mke2fs            mkfs              mkfs.ext3         
mkfs.msdos        mkhybrid          mkmanifest        mkswap
mkdir             mkfifo            mkfs.bfs          mkfs.ext4         
mkfs.reiserfs     mk_isdnhwdb       mknod             mktap
mkdiskimage       mkfontdir         mkfs.cramfs       mkfs.ext4dev      
mkfs.vfat         mkisofs           mkpasswd          mktap-2.7
mkdosfs           mkfontscale       mkfs.ext2         mkfs.minix        
mkhomedir_helper  mklost+found      mkreiserfs        mktemp
root@fireball / #

I have reiserfs3 but I can't find 4.  I didn't see anything in the man 
page either.  I thought it may be a option like -j for ext2 or 3.

Thanks.

Dale

:-)  :-)

Re: [gentoo-user] grub and what happens exactly when booting.

[Pandu Poluan]

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On Sep 16, 2011 5:37 PM, "Dale" <rdalek1967@gmail.com> wrote:
>
> Alan McKinnon wrote:
>>
>> The basic idea is you set the boot drive in the bios and which runs grub
>> from that drive's mbr. When you installed that grub you hard-coded it
>> to know where to find it's grub.conf.
>>
>> You can use the existing grub and it's config files just fine. Add a
>> new entry for your new stuff on sdb - grub will reference that drive as
>> (hd1) in grub.conf - and configure the root, kernel and initrd
>> settings appropriately.
>>
>> If I were you I'd install grub to the mbr on sdb as well. If you happen
>> to switch sda and sdb around, you'll still have code to boot from on
>> the new first drive and not need to change the boot drive settings in
>> the bios. It's not a necessity, just a convenience.
>>
>>
>
> That's what I was thinking.  Now that I got that straight in my head.
 Moooooving on.
>
> I was wanting to play with reiserfs4.  Where in the heck is the command?
 I have this:
>
> root@fireball / # mk << tab twice >>
> mk_cmds           mke2fs            mkfs              mkfs.ext3
mkfs.msdos        mkhybrid          mkmanifest        mkswap
> mkdir             mkfifo            mkfs.bfs          mkfs.ext4
mkfs.reiserfs     mk_isdnhwdb       mknod             mktap
> mkdiskimage       mkfontdir         mkfs.cramfs       mkfs.ext4dev
 mkfs.vfat         mkisofs           mkpasswd          mktap-2.7
> mkdosfs           mkfontscale       mkfs.ext2         mkfs.minix
 mkhomedir_helper  mklost+found      mkreiserfs        mktemp
> root@fireball / #
>
> I have reiserfs3 but I can't find 4.  I didn't see anything in the man
page either.  I thought it may be a option like -j for ext2 or 3.
>

IIRC, you must emerge reiser4.

Try eix reiser

Rgds,

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Re: [gentoo-user] grub and what happens exactly when booting.

[Mick]

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On Friday 16 Sep 2011 11:56:03 Pandu Poluan wrote:
> On Sep 16, 2011 5:37 PM, "Dale" <rdalek1967@gmail.com> wrote:
> > Alan McKinnon wrote:
> >> The basic idea is you set the boot drive in the bios and which runs grub
> >> from that drive's mbr. When you installed that grub you hard-coded it
> >> to know where to find it's grub.conf.
> >> 
> >> You can use the existing grub and it's config files just fine. Add a
> >> new entry for your new stuff on sdb - grub will reference that drive as
> >> (hd1) in grub.conf - and configure the root, kernel and initrd
> >> settings appropriately.
> >> 
> >> If I were you I'd install grub to the mbr on sdb as well. If you happen
> >> to switch sda and sdb around, you'll still have code to boot from on
> >> the new first drive and not need to change the boot drive settings in
> >> the bios. It's not a necessity, just a convenience.
> > 
> > That's what I was thinking.  Now that I got that straight in my head.
> 
>  Moooooving on.
> 
> > I was wanting to play with reiserfs4.  Where in the heck is the command?
> 
>  I have this:
> > root@fireball / # mk << tab twice >>
> > mk_cmds           mke2fs            mkfs              mkfs.ext3
> 
> mkfs.msdos        mkhybrid          mkmanifest        mkswap
> 
> > mkdir             mkfifo            mkfs.bfs          mkfs.ext4
> 
> mkfs.reiserfs     mk_isdnhwdb       mknod             mktap
> 
> > mkdiskimage       mkfontdir         mkfs.cramfs       mkfs.ext4dev
> 
>  mkfs.vfat         mkisofs           mkpasswd          mktap-2.7
> 
> > mkdosfs           mkfontscale       mkfs.ext2         mkfs.minix
> 
>  mkhomedir_helper  mklost+found      mkreiserfs        mktemp
> 
> > root@fireball / #
> > 
> > I have reiserfs3 but I can't find 4.  I didn't see anything in the man
> 
> page either.  I thought it may be a option like -j for ext2 or 3.
> 
> 
> IIRC, you must emerge reiser4.
> 
> Try eix reiser

You will need to patch your kernel (in your sdb test OS) and then you will 
also need to make a reiser4 fs on your sdb partition(s) (for that you'll need 
to emerge sys-fs/reiser4progs).

If you want to be able to mount reiser4 from within your sda OS, you will need 
of course to patch your current kernel to start with, alternatively use a 
LiveCD like sysrescue which comes already patched.  For patches look in here:

http://www.kernel.org/pub/linux/kernel/people/edward/reiser4/reiser4-for-2.6/


The way I do what you are trying to do is start with the existing OS on sda, 
partition sdb, tar contents of sda partitions into corresponding sdb 
partitions and then modify fstab.

Depending on what you want to test you may not need grub installed into sdb's 
MBR and you may not need a /boot in sdb.  As long as you are not going to 
remove sda from the machine you should be able to add a couple of lines in the 
original grub.conf to select to boot /dev/sdb, while using sda's MBR and /boot 
partition.

HTH.
-- 
Regards,
Mick

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Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

Mick wrote:
> You will need to patch your kernel (in your sdb test OS) and then you 
> will also need to make a reiser4 fs on your sdb partition(s) (for that 
> you'll need to emerge sys-fs/reiser4progs). If you want to be able to 
> mount reiser4 from within your sda OS, you will need of course to 
> patch your current kernel to start with, alternatively use a LiveCD 
> like sysrescue which comes already patched. For patches look in here: 
> http://www.kernel.org/pub/linux/kernel/people/edward/reiser4/reiser4-for-2.6/ 
> The way I do what you are trying to do is start with the existing OS 
> on sda, partition sdb, tar contents of sda partitions into 
> corresponding sdb partitions and then modify fstab. Depending on what 
> you want to test you may not need grub installed into sdb's MBR and 
> you may not need a /boot in sdb. As long as you are not going to 
> remove sda from the machine you should be able to add a couple of 
> lines in the original grub.conf to select to boot /dev/sdb, while 
> using sda's MBR and /boot partition. HTH. 

I could have swore reiserfs4 was in the kernel.  Sure enough, it ain't.  
I'll wait then.  I don't want to take the chance that something goes 
belly up then not have a bootable way to fix things.

Now to go unmerge the other since I can't use it anyway.  lol

Thanks.

Dale

:-)  :-)

P. S.  I got new glasses today.  They have bifocals too.  I can actually 
read what I type.  Here comes that turbo charger again.  lol

Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Fri, 16 Sep 2011 10:47:01 -0500
Dale <rdalek1967@gmail.com> wrote:

> Mick wrote:
> > You will need to patch your kernel (in your sdb test OS) and then
> > you will also need to make a reiser4 fs on your sdb partition(s)
> > (for that you'll need to emerge sys-fs/reiser4progs). If you want
> > to be able to mount reiser4 from within your sda OS, you will need
> > of course to patch your current kernel to start with, alternatively
> > use a LiveCD like sysrescue which comes already patched. For
> > patches look in here:
> > http://www.kernel.org/pub/linux/kernel/people/edward/reiser4/reiser4-for-2.6/
> > The way I do what you are trying to do is start with the existing
> > OS on sda, partition sdb, tar contents of sda partitions into
> > corresponding sdb partitions and then modify fstab. Depending on
> > what you want to test you may not need grub installed into sdb's
> > MBR and you may not need a /boot in sdb. As long as you are not
> > going to remove sda from the machine you should be able to add a
> > couple of lines in the original grub.conf to select to
> > boot /dev/sdb, while using sda's MBR and /boot partition. HTH. 
> 
> I could have swore reiserfs4 was in the kernel.  Sure enough, it
> ain't. I'll wait then.  I don't want to take the chance that
> something goes belly up then not have a bootable way to fix things.


reiser4 was never in the kernel and the odds of it ever making it there
were about zero (coding style issues and many other things that pissed
Linux off). And that was in the days when Hans was physically located
in a place where he was allowed to code.

For all practical purposes Reiser4 is dead. I haven't heard a peep out
of anyone claiming to maintain it for a few years now.

-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

Alan McKinnon wrote:
> On Fri, 16 Sep 2011 10:47:01 -0500
> Dale<rdalek1967@gmail.com>  wrote:
>
>> Mick wrote:
>>> You will need to patch your kernel (in your sdb test OS) and then
>>> you will also need to make a reiser4 fs on your sdb partition(s)
>>> (for that you'll need to emerge sys-fs/reiser4progs). If you want
>>> to be able to mount reiser4 from within your sda OS, you will need
>>> of course to patch your current kernel to start with, alternatively
>>> use a LiveCD like sysrescue which comes already patched. For
>>> patches look in here:
>>> http://www.kernel.org/pub/linux/kernel/people/edward/reiser4/reiser4-for-2.6/
>>> The way I do what you are trying to do is start with the existing
>>> OS on sda, partition sdb, tar contents of sda partitions into
>>> corresponding sdb partitions and then modify fstab. Depending on
>>> what you want to test you may not need grub installed into sdb's
>>> MBR and you may not need a /boot in sdb. As long as you are not
>>> going to remove sda from the machine you should be able to add a
>>> couple of lines in the original grub.conf to select to
>>> boot /dev/sdb, while using sda's MBR and /boot partition. HTH.
>> I could have swore reiserfs4 was in the kernel.  Sure enough, it
>> ain't. I'll wait then.  I don't want to take the chance that
>> something goes belly up then not have a bootable way to fix things.
>
> reiser4 was never in the kernel and the odds of it ever making it there
> were about zero (coding style issues and many other things that pissed
> Linux off). And that was in the days when Hans was physically located
> in a place where he was allowed to code.
>
> For all practical purposes Reiser4 is dead. I haven't heard a peep out
> of anyone claiming to maintain it for a few years now.
>

New question.  I'm playing with LVM.  What is the best file system to 
use that with?  I know LVM can shrink and grow so a file system should 
be able to do the same, online would be great but not required.  That 
would be good for a / partition but not needed for the rest.  I can 
always go to single user and resize things.

I don't want XFS tho.  I used it before and it was a total disaster.  I 
have a UPS but I also recall having to pull the plug when hal showed up 
too.  No need for a repeat.

Hmm, maybe I am thinking of ext4?  Life's confusing.  :/

Dale

:-)  :-)

Re: [gentoo-user] grub and what happens exactly when booting.

[Joost Roeleveld]

On Friday, September 16, 2011 11:58:11 AM Dale wrote:
> Alan McKinnon wrote:
> > On Fri, 16 Sep 2011 10:47:01 -0500
> > 
> > Dale<rdalek1967@gmail.com>  wrote:
> >> Mick wrote:
> >>> You will need to patch your kernel (in your sdb test OS) and then
> >>> you will also need to make a reiser4 fs on your sdb partition(s)
> >>> (for that you'll need to emerge sys-fs/reiser4progs). If you want
> >>> to be able to mount reiser4 from within your sda OS, you will need
> >>> of course to patch your current kernel to start with, alternatively
> >>> use a LiveCD like sysrescue which comes already patched. For
> >>> patches look in here:
> >>> http://www.kernel.org/pub/linux/kernel/people/edward/reiser4/reiser4
> >>> -for-2.6/ The way I do what you are trying to do is start with the
> >>> existing OS on sda, partition sdb, tar contents of sda partitions
> >>> into
> >>> corresponding sdb partitions and then modify fstab. Depending on
> >>> what you want to test you may not need grub installed into sdb's
> >>> MBR and you may not need a /boot in sdb. As long as you are not
> >>> going to remove sda from the machine you should be able to add a
> >>> couple of lines in the original grub.conf to select to
> >>> boot /dev/sdb, while using sda's MBR and /boot partition. HTH.
> >> 
> >> I could have swore reiserfs4 was in the kernel.  Sure enough, it
> >> ain't. I'll wait then.  I don't want to take the chance that
> >> something goes belly up then not have a bootable way to fix things.
> > 
> > reiser4 was never in the kernel and the odds of it ever making it there
> > were about zero (coding style issues and many other things that pissed
> > Linux off). And that was in the days when Hans was physically located
> > in a place where he was allowed to code.
> > 
> > For all practical purposes Reiser4 is dead. I haven't heard a peep out
> > of anyone claiming to maintain it for a few years now.
> 
> New question.  I'm playing with LVM.  What is the best file system to
> use that with?  I know LVM can shrink and grow so a file system should
> be able to do the same, online would be great but not required.  That
> would be good for a / partition but not needed for the rest.  I can
> always go to single user and resize things.

LVM is great, when installing a large package, downloading large files or 
finding out I need a lot more diskspace for the VMs I am running to do some 
testing, I can simply increase the LV (LVM-partition) and then increase the 
filesystem to match. All this while the filesystem is being written to.

> I don't want XFS tho.  I used it before and it was a total disaster.  I
> have a UPS but I also recall having to pull the plug when hal showed up
> too.  No need for a repeat.

I know from personal experience that the following support online resizing: 
ext2/3, reiserfs (v3), XFS, JFS.
I would expect ext4 to also support that.

One thing to remember, the online resizing only allows growing of the 
filesystem. For shrinking, you still need to umount it first.
Also, XFS and JFS don't support shrinking at all.

For testing, I would suggest starting with ext3 and/or reiserfs. Both work.
I haven't tried ext4 yet, maybe someone who runs that on top of LVM can 
comment?

> Hmm, maybe I am thinking of ext4?  Life's confusing.  :/

I think you might be thinking of ext4.

Btw, a brief description on how resizing would work.
When growing the filesystem:
1) lvextend .....
2) "resizefs" (different filesystems, different commands)
This will work for all filesystems supporting online resizing. (I know of one 
that actually only allows growing when it IS mounted)

When shrinking a filesystem:
1) umount
2) "resizefs" to less then what you want to shrink it to
3) lvreduce ....
4) "resizefs"

The "resizefs" will default to growing to the full extend of the partition/LV 
it resides on.

--
Joost

PS. With LVM, I find it easier to make the partitions smaller to start with 
and leave un-assigned space in the VG for the LVs to grow.

Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Fri, 16 Sep 2011 11:58:11 -0500
Dale <rdalek1967@gmail.com> wrote:

> Alan McKinnon wrote:
> > On Fri, 16 Sep 2011 10:47:01 -0500
> > Dale<rdalek1967@gmail.com>  wrote:
> >
> >> Mick wrote:
> >>> You will need to patch your kernel (in your sdb test OS) and then
> >>> you will also need to make a reiser4 fs on your sdb partition(s)
> >>> (for that you'll need to emerge sys-fs/reiser4progs). If you want
> >>> to be able to mount reiser4 from within your sda OS, you will need
> >>> of course to patch your current kernel to start with,
> >>> alternatively use a LiveCD like sysrescue which comes already
> >>> patched. For patches look in here:
> >>> http://www.kernel.org/pub/linux/kernel/people/edward/reiser4/reiser4-for-2.6/
> >>> The way I do what you are trying to do is start with the existing
> >>> OS on sda, partition sdb, tar contents of sda partitions into
> >>> corresponding sdb partitions and then modify fstab. Depending on
> >>> what you want to test you may not need grub installed into sdb's
> >>> MBR and you may not need a /boot in sdb. As long as you are not
> >>> going to remove sda from the machine you should be able to add a
> >>> couple of lines in the original grub.conf to select to
> >>> boot /dev/sdb, while using sda's MBR and /boot partition. HTH.
> >> I could have swore reiserfs4 was in the kernel.  Sure enough, it
> >> ain't. I'll wait then.  I don't want to take the chance that
> >> something goes belly up then not have a bootable way to fix things.
> >
> > reiser4 was never in the kernel and the odds of it ever making it
> > there were about zero (coding style issues and many other things
> > that pissed Linux off). And that was in the days when Hans was
> > physically located in a place where he was allowed to code.
> >
> > For all practical purposes Reiser4 is dead. I haven't heard a peep
> > out of anyone claiming to maintain it for a few years now.
> >
> 
> New question.  I'm playing with LVM.  What is the best file system to 
> use that with?

The best one to use is the one you want to use.

LVM has nothing to do with type of filesystem, there is no such thing
as this one works and that one doesn't. So pick the one that suits your
needs.

>  I know LVM can shrink and grow so a file system
> should be able to do the same, online would be great but not
> required.  That would be good for a / partition but not needed for
> the rest.  I can always go to single user and resize things.

Wrong question. See above.

> 
> I don't want XFS tho.  I used it before and it was a total disaster.
> I have a UPS but I also recall having to pull the plug when hal
> showed up too.  No need for a repeat.
> 
> Hmm, maybe I am thinking of ext4?  Life's confusing.  :/

ext4 is fine for your needs. I will be mighty surprised if your usage
ever hits ext4's limits.


-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Peter Humphrey]

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On Friday 16 September 2011 17:58:11 Dale wrote:

> Hmm, maybe I am thinking of ext4?  Life's confusing.  :/

In case it helps, here's the relevant part of my fstab:

/dev/sda1           /boot               ext2    noatime,noauto 1 2
/dev/md3            /                   ext4    noatime        1 1
/dev/vg1/home       /home               ext4    noatime        1 2
/dev/vg1/common     /home/prh/common    ext4    noatime        1 3
/dev/vg1/boinc      /home/prh/boinc     ext4    noatime        1 3
/dev/vg1/virt       /home/prh/.VirtualBox  ext4 noatime        1 3
/dev/vg1/portage    /usr/portage        ext4    noatime        1 2
/dev/vg1/packages   /usr/portage/packages  ext4 noatime        1 3
/dev/vg1/distfiles  /usr/portage/distfiles ext4 noatime        1 3
/dev/vg1/local      /usr/local          ext4    noatime        1 2
/dev/vg1/opt        /opt                ext4    noatime        1 2
/dev/vg1/srv        /srv                ext4    noatime        1 2
/dev/vg1/chroot     /mnt/atom           ext4    noatime        1 2

The common partition is where I keep my user stuff that is common among 
distros. Boinc is where boinc runs, and virt is where VirtualBox runs. I 
don't know why I still have a srv there, as Gentoo doesn't use it (maybe I 
should reallocate it to /var or /var/tmp). Chroot is where I mount my Atom 
box's portage directory so that I can use the workstation to build packages 
for binary installation on the Atom box - saves oodles of time and heat.

I have a /dev/vg2 as well, for experimental installation of other distros; 
those that can be installed into virtual partitions, that is.

The following commands would re-create those partitions and file systems, 
having created the physical volume and the volume group vg1:

lvcreate -L 10G -n opt vg1
lvcreate -L 12G -n distfiles vg1
lvcreate -L 12G -n srv vg1
lvcreate -L 15G -n home vg1
lvcreate -L 15G -n virt vg1
lvcreate -L 20G -n boinc vg1
lvcreate -L 20G -n chroot vg1
lvcreate -L 20G -n packages vg1
lvcreate -L 2G -n local vg1
lvcreate -L 50G -n common vg1
lvcreate -L 8G -n portage vg1
mkfs.ext4 -j -O dir_index /dev/vg1/boinc
mkfs.ext4 -j -O dir_index /dev/vg1/chroot
mkfs.ext4 -j -O dir_index /dev/vg1/common
mkfs.ext4 -j -O dir_index /dev/vg1/distfiles
mkfs.ext4 -j -O dir_index /dev/vg1/home
mkfs.ext4 -j -O dir_index /dev/vg1/local
mkfs.ext4 -j -O dir_index /dev/vg1/opt
mkfs.ext4 -j -O dir_index /dev/vg1/packages
mkfs.ext4 -j -O dir_index /dev/vg1/portage
mkfs.ext4 -j -O dir_index /dev/vg1/srv
mkfs.ext4 -j -O dir_index /dev/vg1/virt

That list was created by David Noon's zsh script, which he posted here 
recently. In fact I have file-systm labels written by mkfs.ext4 as well, but 
David's script doesn't notice those.

Sda and sdb are 1TB SATA Samsung devices.

HTH.

-- 
Rgds
Peter		Linux Counter 5290, 1994-04-23

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Re: [gentoo-user] grub and what happens exactly when booting.

[Neil Bothwick]

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On Fri, 16 Sep 2011 22:03:20 +0100, Peter Humphrey wrote:

> In case it helps, here's the relevant part of my fstab:
> 
> /dev/sda1           /boot               ext2    noatime,noauto 1 2
> /dev/md3            /                   ext4    noatime        1 1
> /dev/vg1/home       /home               ext4    noatime
> 1 2

A word of advice when starting from scratch, give your VG(s) unique
names. I've seen what happens when someone takes a drive from
one Fedora system and puts it in another, so there are two VGs called
vg01. It ain't nice (only one is seen, usually not the one you want).

I prefer to give my VGs names related to the hostname, so it's perfectly
clear where they came from and no risk of name collisions if I have to
attach the drive to another computer.


-- 
Neil Bothwick

Happiness is merely the remission of pain.

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Re: [gentoo-user] grub and what happens exactly when booting.

[Peter Humphrey]

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On Friday 16 September 2011 23:13:27 Neil Bothwick wrote:

> A word of advice when starting from scratch, give your VG(s) unique
> names. I've seen what happens when someone takes a drive from
> one Fedora system and puts it in another, so there are two VGs called
> vg01. It ain't nice (only one is seen, usually not the one you want).

That would be nasty, yes, but here at home I don't expect to be switching 
disks around between machines.

I did give a bit of thought to a VG naming scheme, but although several 
ideas came up, nothing was clearly the best so I left them at vg1 and vg2.

-- 
Rgds
Peter		Linux Counter 5290, 1994-04-23

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Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

Neil Bothwick wrote:
> On Fri, 16 Sep 2011 22:03:20 +0100, Peter Humphrey wrote:
>
>> In case it helps, here's the relevant part of my fstab:
>>
>> /dev/sda1           /boot               ext2    noatime,noauto 1 2
>> /dev/md3            /                   ext4    noatime        1 1
>> /dev/vg1/home       /home               ext4    noatime
>> 1 2
> A word of advice when starting from scratch, give your VG(s) unique
> names. I've seen what happens when someone takes a drive from
> one Fedora system and puts it in another, so there are two VGs called
> vg01. It ain't nice (only one is seen, usually not the one you want).
>
> I prefer to give my VGs names related to the hostname, so it's perfectly
> clear where they came from and no risk of name collisions if I have to
> attach the drive to another computer.
>
>

I did name it pretty well.  It is called "test" right now.  lol  Right 
now, I'm just having fun.  The biggest difference so far is that I can 
see with my new glasses.  I just wish I didn't have arthritis in my neck 
and could move my head better.  It's hard to switch between normal and 
the bifocal thingys.

I'm getting this LVM thing down pat tho.

cfdisk to create partitions, if not using the whole drive.
pvcreate
vgcreate
lvcreate
then put on a file system and mount.

I still get them confused as to what comes first but I got some pictures 
to look at now.  That helps to picture what I am doing, sort of.

Thanks to all for the advice tho.  It's helping.  Still nervous about / 
on LVM tho.  :/

Dale

:-)  :-)

Re: [gentoo-user] grub and what happens exactly when booting.

[Peter Humphrey]

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On Saturday 17 September 2011 01:06:40 Dale wrote:

> Still nervous about / on LVM tho.  :/

Me too. That's why my / is on /dev/md3, which combines /dev/sd[ab]3 in 
RAID-1.

-- 
Rgds
Peter		Linux Counter 5290, 1994-04-23

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Re: [gentoo-user] grub and what happens exactly when booting.

[Gregory Shearman]

In linux.gentoo.user, Dale wrote:
>
> I'm getting this LVM thing down pat tho.
>
> cfdisk to create partitions, if not using the whole drive.
> pvcreate
> vgcreate
> lvcreate
> then put on a file system and mount.

Sounds good.

> I still get them confused as to what comes first but I got some pictures 
> to look at now.  That helps to picture what I am doing, sort of.

pv = physical volume. Physical comes first.

vg = volume group. LVM volumes MUST belong to a group.

lv = logical volume. Logical obviously comes last.

> Thanks to all for the advice tho.  It's helping.  Still nervous about / 
> on LVM tho.  :/

If you're nervous then don't do it. I've had my root filesystem on LVM
for years on a number of different machines and never had a problem.
I've used Genkernel's initramfs generator to create my initramfs, but
I've just unmasked dracut and I've begun testing it on my system. It
looks good so far, except that dracut mounts something on my nonexistent
/run directory. This caused a warning when displaying mounted
filesystems using "df" about /run not existing. I'm wondering whether I
can just add the directory or do I need to do something special such as
add a ".keep" file to it.

If you want to go ahead with root on LVM then leave a duplicate root
partition in a normal linux partition until you're satisfied, or backup
your root partition to another machine or disk drive. You should be
backing up your system anyway. My root filesystem on my laptop is only
161MB. Of course I've got a separate /usr and /var filesystem, which is
the reason for my testing of dracut. I want to be ahead of the game when
these forced udev changes become mandatory.

I'm not happy about the decision to make /usr necessary for udev to
populate /dev, but I've used an initramfs for years so it's not such a
wrench for as it for other gentoo users.

-- 
Regards,
Gregory.

Re: [gentoo-user] grub and what happens exactly when booting.

[William Kenworthy]

On Fri, 2011-09-16 at 19:06 -0500, Dale wrote:
> Neil Bothwick wrote:
> > On Fri, 16 Sep 2011 22:03:20 +0100, Peter Humphrey wrote:
> >
> >> In case it helps, here's the relevant part of my fstab:
> >>
> >> /dev/sda1           /boot               ext2    noatime,noauto 1 2
> >> /dev/md3            /                   ext4    noatime        1 1
> >> /dev/vg1/home       /home               ext4    noatime
> >> 1 2
> > A word of advice when starting from scratch, give your VG(s) unique
> > names. I've seen what happens when someone takes a drive from
> > one Fedora system and puts it in another, so there are two VGs called
> > vg01. It ain't nice (only one is seen, usually not the one you want).
> >
> > I prefer to give my VGs names related to the hostname, so it's perfectly
> > clear where they came from and no risk of name collisions if I have to
> > attach the drive to another computer.
> >
> >
> 
> I did name it pretty well.  It is called "test" right now.  lol  Right 
> now, I'm just having fun.  The biggest difference so far is that I can 
> see with my new glasses.  I just wish I didn't have arthritis in my neck 
> and could move my head better.  It's hard to switch between normal and 
> the bifocal thingys.

try multifocal - makes stairs ... fun.

> 
> I'm getting this LVM thing down pat tho.
> 
> cfdisk to create partitions, if not using the whole drive.
> pvcreate
> vgcreate
> lvcreate
> then put on a file system and mount.
> 
> I still get them confused as to what comes first but I got some pictures 
> to look at now.  That helps to picture what I am doing, sort of.
> 
> Thanks to all for the advice tho.  It's helping.  Still nervous about / 
> on LVM tho.  :/
> 
> Dale
> 
> :-)  :-)
> 

I'll second the recommendation about naming ... I use separate
partitions and lvm on everything except root (for recovery reasons) and
small single drive systems ... been a real saver when partitions fill up
or when a system is re-purposed and you have to change the storage
profile .  Make sure every lvm you use is uniquely named ... I am just
going through retrieving drives from two older (both lvm) systems and
pushing them into a single storage (and everything else) sever, also
lvm.

Make sure if you remove a drive and dont intend using it immediately,
delete the lvm data to prevent future grief ... it can happen at home as
well as in data centres :)

BillK

Re: [gentoo-user] grub and what happens exactly when booting.

[Alex Schuster]

Dale writes:

> Neil Bothwick wrote:
> > On Fri, 16 Sep 2011 22:03:20 +0100, Peter Humphrey wrote:

> > A word of advice when starting from scratch, give your VG(s) unique
> > names. I've seen what happens when someone takes a drive from
> > one Fedora system and puts it in another, so there are two VGs called
> > vg01. It ain't nice (only one is seen, usually not the one you want).
> >
> > I prefer to give my VGs names related to the hostname, so it's
> > perfectly clear where they came from and no risk of name collisions
> > if I have to attach the drive to another computer.

I had such a collision once, but I was able to change the name of one
volume group by using vgrename with the UUID that vgdisplay shows. Dale,
unless you know about them already, check out {pv,vg,lv}{scan,display} for
information about your LVM.

> I did name it pretty well.  It is called "test" right now.  lol  Right 
> now, I'm just having fun.  The biggest difference so far is that I can 
> see with my new glasses.  I just wish I didn't have arthritis in my
> neck and could move my head better.  It's hard to switch between normal
> and the bifocal thingys.
> 
> I'm getting this LVM thing down pat tho.

Finally!

> cfdisk to create partitions, if not using the whole drive.

I like to create several partitions, not a single one. And use pvcreate
for every partition then. This way, I can free space later just in case I
somehow need to have a conventional partition for installing Windows or
something. pvmove can transfer stuff from one physical volume to another.

I also used to have two volume groups. One small one for the system at
the start of the drive, where it is supposed to be a little faster, and
another big one for the rest. But I stopped doing so, as I lose a little
flexibility, and the effect is probably negligible, as all stuff is
encrypted here.

	Wonko

Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

[-- Attachment #1: Type: text/plain, Size: 4582 bytes --]

Peter Humphrey wrote:
>
> On Friday 16 September 2011 17:58:11 Dale wrote:
>
>
> > Hmm, maybe I am thinking of ext4? Life's confusing. :/
>
>
> In case it helps, here's the relevant part of my fstab:
>
>
> /dev/sda1 /boot ext2 noatime,noauto 1 2
>
> /dev/md3 / ext4 noatime 1 1
>
> /dev/vg1/home /home ext4 noatime 1 2
>
> /dev/vg1/common /home/prh/common ext4 noatime 1 3
>
> /dev/vg1/boinc /home/prh/boinc ext4 noatime 1 3
>
> /dev/vg1/virt /home/prh/.VirtualBox ext4 noatime 1 3
>
> /dev/vg1/portage /usr/portage ext4 noatime 1 2
>
> /dev/vg1/packages /usr/portage/packages ext4 noatime 1 3
>
> /dev/vg1/distfiles /usr/portage/distfiles ext4 noatime 1 3
>
> /dev/vg1/local /usr/local ext4 noatime 1 2
>
> /dev/vg1/opt /opt ext4 noatime 1 2
>
> /dev/vg1/srv /srv ext4 noatime 1 2
>
> /dev/vg1/chroot /mnt/atom ext4 noatime 1 2
>
>
> The common partition is where I keep my user stuff that is common 
> among distros. Boinc is where boinc runs, and virt is where VirtualBox 
> runs. I don't know why I still have a srv there, as Gentoo doesn't use 
> it (maybe I should reallocate it to /var or /var/tmp). Chroot is where 
> I mount my Atom box's portage directory so that I can use the 
> workstation to build packages for binary installation on the Atom box 
> - saves oodles of time and heat.
>
>
> I have a /dev/vg2 as well, for experimental installation of other 
> distros; those that can be installed into virtual partitions, that is.
>
>
> The following commands would re-create those partitions and file 
> systems, having created the physical volume and the volume group vg1:
>
>
> lvcreate -L 10G -n opt vg1
>
> lvcreate -L 12G -n distfiles vg1
>
> lvcreate -L 12G -n srv vg1
>
> lvcreate -L 15G -n home vg1
>
> lvcreate -L 15G -n virt vg1
>
> lvcreate -L 20G -n boinc vg1
>
> lvcreate -L 20G -n chroot vg1
>
> lvcreate -L 20G -n packages vg1
>
> lvcreate -L 2G -n local vg1
>
> lvcreate -L 50G -n common vg1
>
> lvcreate -L 8G -n portage vg1
>
> mkfs.ext4 -j -O dir_index /dev/vg1/boinc
>
> mkfs.ext4 -j -O dir_index /dev/vg1/chroot
>
> mkfs.ext4 -j -O dir_index /dev/vg1/common
>
> mkfs.ext4 -j -O dir_index /dev/vg1/distfiles
>
> mkfs.ext4 -j -O dir_index /dev/vg1/home
>
> mkfs.ext4 -j -O dir_index /dev/vg1/local
>
> mkfs.ext4 -j -O dir_index /dev/vg1/opt
>
> mkfs.ext4 -j -O dir_index /dev/vg1/packages
>
> mkfs.ext4 -j -O dir_index /dev/vg1/portage
>
> mkfs.ext4 -j -O dir_index /dev/vg1/srv
>
> mkfs.ext4 -j -O dir_index /dev/vg1/virt
>
>
> That list was created by David Noon's zsh script, which he posted here 
> recently. In fact I have file-systm labels written by mkfs.ext4 as 
> well, but David's script doesn't notice those.
>
>
> Sda and sdb are 1TB SATA Samsung devices.
>
>
> HTH.
>
>
> -- 
>
> Rgds
>
> Peter Linux Counter 5290, 1994-04-23
>
>

Interesting read and it helps.  I sort of understand LVM and realize its 
benefits but just concerned about something breaking and me sitting here 
with no clue how to fix it.  Of course, Knoppix and gmails web mail may 
help tho.  ;-)  Thanks for posting fstab too.  That gives me some clues 
on how to do mine.  Clues are good.

I have copied over with the following:

/boot on its partition
/ on its partition
/home on LVM
/usr on LVM
/var on LVM

Then I ran into this:

/dev/sdb3              9614148   1526468   7599304  17% /mnt/gentoo
/dev/sdb1               280003     11568    253979   5% /mnt/gentoo/boot
/dev/mapper/test-home
                       51606140  10289244  38695456  22% /mnt/gentoo/home
/dev/mapper/test-usr  14449712  10841540   2874172  80% /mnt/gentoo/usr
/dev/mapper/test-var  12385456   6405360   5350952  55% /mnt/gentoo/var


Ooops, /usr is almost full.  Well that ain't good at all is it?  Well 
looky here:

/dev/sdb3              9614148   1526468   7599304  17% /mnt/gentoo
/dev/sdb1               280003     11568    253979   5% /mnt/gentoo/boot
/dev/mapper/test-home
                       51606140  10289244  38695456  22% /mnt/gentoo/home
/dev/mapper/test-usr  20642428  10845076   8748856  56% /mnt/gentoo/usr
/dev/mapper/test-var  12385456   6405360   5350952  55% /mnt/gentoo/var

That was like 5 minutes later and it was mounted the whole time too.  
Yep, it's pretty neat.  Now to work on this init crap.  I read a couple 
howtos but it is still murky.  It'll sort out as I get started I guess.

I'm using ext4 by the way.  It's been out a while and sounds like it is 
stable.

Does LVM make the heads move around more or anything like that?  I'm 
just thinking it would depending on what lv are on what drives.  I 
dunno, just curious.

Thanks.

Dale

:-)  :-)

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Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

William Kenworthy wrote:
> On Fri, 2011-09-16 at 19:06 -0500, Dale wrote:
>> Neil Bothwick wrote:
>> I did name it pretty well. It is called "test" right now. lol Right 
>> now, I'm just having fun. The biggest difference so far is that I can 
>> see with my new glasses. I just wish I didn't have arthritis in my 
>> neck and could move my head better. It's hard to switch between 
>> normal and the bifocal thingys. 
> try multifocal - makes stairs ... fun.

It was night time and I was walking.  I decided to walk through the 
garden which means crossing the ditch.  Let's just say that first step 
was fun.  When I looked at the ground, I was looking through the reading 
part.  I found out it was deeper than my eyes said.

>
>> I'm getting this LVM thing down pat tho.
>>
>> cfdisk to create partitions, if not using the whole drive.
>> pvcreate
>> vgcreate
>> lvcreate
>> then put on a file system and mount.
>>
>> I still get them confused as to what comes first but I got some pictures
>> to look at now.  That helps to picture what I am doing, sort of.
>>
>> Thanks to all for the advice tho.  It's helping.  Still nervous about /
>> on LVM tho.  :/
>>
>> Dale
>>
>> :-)  :-)
>>
> I'll second the recommendation about naming ... I use separate
> partitions and lvm on everything except root (for recovery reasons) and
> small single drive systems ... been a real saver when partitions fill up
> or when a system is re-purposed and you have to change the storage
> profile .  Make sure every lvm you use is uniquely named ... I am just
> going through retrieving drives from two older (both lvm) systems and
> pushing them into a single storage (and everything else) sever, also
> lvm.
>
> Make sure if you remove a drive and dont intend using it immediately,
> delete the lvm data to prevent future grief ... it can happen at home as
> well as in data centres :)
>
> BillK
>

Should I include the drive itself?  Like sda, sdb etc.  I could use my 
system name too.  I'm on fireball and my older rig is named smoker.  See 
a trend here?  lol  Anyway, this could work:

fireball-sda
fireball-sdb
fireball-sdc

That would keep things straight I would think.  Thoughts?

If I do move one tho, I would likely erase the LVM stuff anyway.  This 
rig is amd64 and my old rig is x86.  It's not like I can move one to the 
other.  Plus, smoker is IDE and fireball is SATA.  I do have one IDE 
connector in fireball and a SATA card in smoker tho.  It could happen.

Jeepers, this could turn into a full blown meeting of the minds.  O_O

Dale

:-)  :-)

Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

Dale wrote:
> William Kenworthy wrote:
>> On Fri, 2011-09-16 at 19:06 -0500, Dale wrote:
>>> Neil Bothwick wrote:
>>> I did name it pretty well. It is called "test" right now. lol Right 
>>> now, I'm just having fun. The biggest difference so far is that I 
>>> can see with my new glasses. I just wish I didn't have arthritis in 
>>> my neck and could move my head better. It's hard to switch between 
>>> normal and the bifocal thingys. 
>> try multifocal - makes stairs ... fun.
>
> It was night time and I was walking.  I decided to walk through the 
> garden which means crossing the ditch.  Let's just say that first step 
> was fun.  When I looked at the ground, I was looking through the 
> reading part.  I found out it was deeper than my eyes said.
>
>>
>>> I'm getting this LVM thing down pat tho.
>>>
>>> cfdisk to create partitions, if not using the whole drive.
>>> pvcreate
>>> vgcreate
>>> lvcreate
>>> then put on a file system and mount.
>>>
>>> I still get them confused as to what comes first but I got some 
>>> pictures
>>> to look at now.  That helps to picture what I am doing, sort of.
>>>
>>> Thanks to all for the advice tho.  It's helping.  Still nervous about /
>>> on LVM tho.  :/
>>>
>>> Dale
>>>
>>> :-)  :-)
>>>
>> I'll second the recommendation about naming ... I use separate
>> partitions and lvm on everything except root (for recovery reasons) and
>> small single drive systems ... been a real saver when partitions fill up
>> or when a system is re-purposed and you have to change the storage
>> profile .  Make sure every lvm you use is uniquely named ... I am just
>> going through retrieving drives from two older (both lvm) systems and
>> pushing them into a single storage (and everything else) sever, also
>> lvm.
>>
>> Make sure if you remove a drive and dont intend using it immediately,
>> delete the lvm data to prevent future grief ... it can happen at home as
>> well as in data centres :)
>>
>> BillK
>>
>
> Should I include the drive itself?  Like sda, sdb etc.  I could use my 
> system name too.  I'm on fireball and my older rig is named smoker.  
> See a trend here?  lol  Anyway, this could work:
>
> fireball-sda
> fireball-sdb
> fireball-sdc
>
> That would keep things straight I would think.  Thoughts?
>
> If I do move one tho, I would likely erase the LVM stuff anyway.  This 
> rig is amd64 and my old rig is x86.  It's not like I can move one to 
> the other.  Plus, smoker is IDE and fireball is SATA.  I do have one 
> IDE connector in fireball and a SATA card in smoker tho.  It could 
> happen.
>
> Jeepers, this could turn into a full blown meeting of the minds.  O_O
>
> Dale
>
> :-)  :-)
>

Well, actually the drive won't work because it could be on any drive.  
Looks like hostname/system name is the best way.  Thoughts?

Dale

:-)  :-)

Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Sat, 17 Sep 2011 00:49:21 +0100
Peter Humphrey <peter@humphrey.ukfsn.org> wrote:

> On Friday 16 September 2011 23:13:27 Neil Bothwick wrote:
> 
> > A word of advice when starting from scratch, give your VG(s) unique
> > names. I've seen what happens when someone takes a drive from
> > one Fedora system and puts it in another, so there are two VGs
> > called vg01. It ain't nice (only one is seen, usually not the one
> > you want).
> 
> That would be nasty, yes, but here at home I don't expect to be
> switching disks around between machines.
> 
> I did give a bit of thought to a VG naming scheme, but although
> several ideas came up, nothing was clearly the best so I left them at
> vg1 and vg2.
> 

This is what GUIDs are for.

They are not the best thing to work with admittedly, but they are
guaranteed to be unique for all reasonable human needs. In a world
when we plug things out of anything and plug them back into anything,
a guaranteed unique ID is a necessaity.

 

-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Fri, 16 Sep 2011 19:06:40 -0500
Dale <rdalek1967@gmail.com> wrote:

> Neil Bothwick wrote:
> > On Fri, 16 Sep 2011 22:03:20 +0100, Peter Humphrey wrote:
> >
> >> In case it helps, here's the relevant part of my fstab:
> >>
> >> /dev/sda1           /boot               ext2    noatime,noauto 1 2
> >> /dev/md3            /                   ext4    noatime        1 1
> >> /dev/vg1/home       /home               ext4    noatime
> >> 1 2
> > A word of advice when starting from scratch, give your VG(s) unique
> > names. I've seen what happens when someone takes a drive from
> > one Fedora system and puts it in another, so there are two VGs
> > called vg01. It ain't nice (only one is seen, usually not the one
> > you want).
> >
> > I prefer to give my VGs names related to the hostname, so it's
> > perfectly clear where they came from and no risk of name collisions
> > if I have to attach the drive to another computer.
> >
> >
> 
> I did name it pretty well.  It is called "test" right now.  lol
> Right now, I'm just having fun.  The biggest difference so far is
> that I can see with my new glasses.  I just wish I didn't have
> arthritis in my neck and could move my head better.  It's hard to
> switch between normal and the bifocal thingys.
> 
> I'm getting this LVM thing down pat tho.
> 
> cfdisk to create partitions, if not using the whole drive.
> pvcreate
> vgcreate
> lvcreate
> then put on a file system and mount.
> 
> I still get them confused as to what comes first but I got some
> pictures to look at now.  That helps to picture what I am doing, sort
> of.
> 
> Thanks to all for the advice tho.  It's helping.  Still nervous
> about / on LVM tho.  :/


Your list is upside down :-) Turn it the other way in your head and it
all makes sense, fs at the top and pv at the bottom and the order makes
sense. A useful mental trick is to remember that each thing in the list
can't be bigger than the one below it (you can't put a 200G fs on a
100G block device for example). Take the list:

fs
lv
vg
pv
disk partition
raw disk

To make a bigger fs, you need a bigger lv first. You have free space
in the vg, so you can just extend the lv into it, then grow the fs
(this is conceptually identical to making a disk partition bigger then
growing the fs if you don't use LVM). 

To make a smaller fs, reduce the fs first then reduce the lv to match.

The one slight oddity is making a vg bigger and smaller - a vg isn't
like a volume that you can make bigger, it's a *group* of things,
specifically pvs. To make a vg bigger, you add pvs to it. To make a vg
smaller, you take pvs away (much like enlarging and reducing RAID
arrays - you add and remove disks).

Once you've worked it through it in your head once or twice it all
makes sense. Users just gotta spend the 30 minutes doing that first.


-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Sat, 17 Sep 2011 06:44:47 -0500
Dale <rdalek1967@gmail.com> wrote:

> Should I include the drive itself?  Like sda, sdb etc.  I could use
> my system name too.  I'm on fireball and my older rig is named
> smoker.  See a trend here?  lol  Anyway, this could work:
> 
> fireball-sda
> fireball-sdb
> fireball-sdc

That's not a good naming scheme, the names depend on what a specific
machine will do with them. Rather come up with a naming scheme that
depends on what the drive IS

dale-seagate-old 320G
dale-seagate-new-660G
dale-quantum-73G

or what you intend to DO with it

dale-root-oldrig
dale-photos-small
dale-photos-big
dale-music


-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Neil Bothwick]

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On Sat, 17 Sep 2011 00:49:21 +0100, Peter Humphrey wrote:

> > A word of advice when starting from scratch, give your VG(s) unique
> > names. I've seen what happens when someone takes a drive from
> > one Fedora system and puts it in another, so there are two VGs called
> > vg01. It ain't nice (only one is seen, usually not the one you
> > want).  
> 
> That would be nasty, yes, but here at home I don't expect to be
> switching disks around between machines.

A motherboard fails so you connect the disk to your new computer to
retrieve the data and it disappears. It happens too often :(


-- 
Neil Bothwick

"Daddy, what does formatting drive 'C' mean?

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Re: [gentoo-user] grub and what happens exactly when booting.

[Peter Humphrey]

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On Saturday 17 September 2011 13:44:39 Alan McKinnon wrote:

> [GUIDs] are not the best thing to work with admittedly, but they are
> guaranteed to be unique for all reasonable human needs. In a world
> when we plug things out of anything and plug them back into anything,
> a guaranteed unique ID is a necessaity.

As I said, I do not expect to move hard disks around willy-nilly in my 
boxes, so it certainly isn't a necessity - I don't have an armada of 
hundreds of boxes here. And I still haven't seen a compelling reason not to 
quote, e.g., /dev/sda3 in fstab. I know where my partitions are and I want 
to continue to know that. Call it control-freakery if you like, but it's at 
the core of sys-admin (if I may say that to you, Alan).

-- 
Rgds
Peter		Linux Counter 5290, 1994-04-23

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Re: [gentoo-user] grub and what happens exactly when booting.

[Peter Humphrey]

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On Saturday 17 September 2011 12:34:54 Dale wrote:

> Does LVM make the heads move around more or anything like that?  I'm
> just thinking it would depending on what lv are on what drives.  I
> dunno, just curious.

I haven't thought about that, but my first impression is that LVM won't make 
any great difference. The data get stored where the data get stored, if you 
see what I mean. How they're organised is in the implementation layers. (Am 
I making sense? It's getting late here.)

-- 
Rgds
Peter		Linux Counter 5290, 1994-04-23

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Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Sun, 18 Sep 2011 23:02:45 +0100
Peter Humphrey <peter@humphrey.ukfsn.org> wrote:

> On Saturday 17 September 2011 13:44:39 Alan McKinnon wrote:
> 
> > [GUIDs] are not the best thing to work with admittedly, but they are
> > guaranteed to be unique for all reasonable human needs. In a world
> > when we plug things out of anything and plug them back into
> > anything, a guaranteed unique ID is a necessaity.
> 
> As I said, I do not expect to move hard disks around willy-nilly in
> my boxes, so it certainly isn't a necessity - I don't have an armada
> of hundreds of boxes here. And I still haven't seen a compelling
> reason not to quote, e.g., /dev/sda3 in fstab. I know where my
> partitions are and I want to continue to know that. Call it
> control-freakery if you like, but it's at the core of sys-admin (if I
> may say that to you, Alan).
> 

Well, if you are completely confident you can deal with anything that
comes up, you should just continue doing what you've always done.
That's part of good sysadmining.

I express my own paranoia in a different way :-)

-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

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Peter Humphrey wrote:
>
> On Saturday 17 September 2011 12:34:54 Dale wrote:
>
>
> > Does LVM make the heads move around more or anything like that? I'm
>
> > just thinking it would depending on what lv are on what drives. I
>
> > dunno, just curious.
>
>
> I haven't thought about that, but my first impression is that LVM 
> won't make any great difference. The data get stored where the data 
> get stored, if you see what I mean. How they're organised is in the 
> implementation layers. (Am I making sense? It's getting late here.)
>
>
> -- 
>
> Rgds
>
> Peter Linux Counter 5290, 1994-04-23
>
>


Yea, I see the point.  I was even thinking that if LVM is on multiple 
drives and the a lv was spanned across two or more drives, then it could 
even be faster.  Data spanned across two or more drives could result in 
it reading more data faster since both drives are collecting data at 
about the same time.

But then again, it depends on how the data is spread out too.  I guess 
it is six of one and half a dozen of the other.

Dale

:-)  :-)

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Re: [gentoo-user] grub and what happens exactly when booting.

[Pandu Poluan]

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On Sep 19, 2011 11:12 AM, "Dale" <rdalek1967@gmail.com> wrote:
>
> Peter Humphrey wrote:
>>
>> On Saturday 17 September 2011 12:34:54 Dale wrote:
>>
>>
>> > Does LVM make the heads move around more or anything like that? I'm
>>
>> > just thinking it would depending on what lv are on what drives. I
>>
>> > dunno, just curious.
>>
>>
>> I haven't thought about that, but my first impression is that LVM won't
make any great difference. The data get stored where the data get stored, if
you see what I mean. How they're organised is in the implementation layers.
(Am I making sense? It's getting late here.)
>>
>>
>> --
>>
>> Rgds
>>
>> Peter Linux Counter 5290, 1994-04-23
>>
>>
>
>
> Yea, I see the point.  I was even thinking that if LVM is on multiple
drives and the a lv was spanned across two or more drives, then it could
even be faster.  Data spanned across two or more drives could result in it
reading more data faster since both drives are collecting data at about the
same time.
>
> But then again, it depends on how the data is spread out too.  I guess it
is six of one and half a dozen of the other.
>

I'm not sure if LVM by itself implement striping. Most likely not because
LVM usually starts with 1 HD then gets additional PVs added. Plus there's
the possibility that the second PV has a different size.

I might be wrong, though, since all my experience with LVM involves only one
drive.

Rgds,

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Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Mon, 19 Sep 2011 13:51:03 +0700
Pandu Poluan <pandu@poluan.info> wrote:

> On Sep 19, 2011 11:12 AM, "Dale" <rdalek1967@gmail.com> wrote:
> >
> > Peter Humphrey wrote:
> >>
> >> On Saturday 17 September 2011 12:34:54 Dale wrote:
> >>
> >>
> >> > Does LVM make the heads move around more or anything like that?
> >> > I'm
> >>
> >> > just thinking it would depending on what lv are on what drives. I
> >>
> >> > dunno, just curious.
> >>
> >>
> >> I haven't thought about that, but my first impression is that LVM
> >> won't
> make any great difference. The data get stored where the data get
> stored, if you see what I mean. How they're organised is in the
> implementation layers. (Am I making sense? It's getting late here.)
> >>
> >>
> >> --
> >>
> >> Rgds
> >>
> >> Peter Linux Counter 5290, 1994-04-23
> >>
> >>
> >
> >
> > Yea, I see the point.  I was even thinking that if LVM is on
> > multiple
> drives and the a lv was spanned across two or more drives, then it
> could even be faster.  Data spanned across two or more drives could
> result in it reading more data faster since both drives are
> collecting data at about the same time.
> >
> > But then again, it depends on how the data is spread out too.  I
> > guess it
> is six of one and half a dozen of the other.
> >
> 
> I'm not sure if LVM by itself implement striping. Most likely not
> because LVM usually starts with 1 HD then gets additional PVs added.
> Plus there's the possibility that the second PV has a different size.
> 
> I might be wrong, though, since all my experience with LVM involves
> only one drive.


LVM does do striping according to the man page. I've never tried it,
mostly because LVM is the wrong place to do that IMHO.

Use RAID for that instead and leave LVM to do what it's good at -
managing storage volumes


-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Dale]

Alan McKinnon wrote:
> On Mon, 19 Sep 2011 13:51:03 +0700
> Pandu Poluan<pandu@poluan.info>  wrote:
>
>> On Sep 19, 2011 11:12 AM, "Dale"<rdalek1967@gmail.com>  wrote:
>>> Peter Humphrey wrote:
>>>> On Saturday 17 September 2011 12:34:54 Dale wrote:
>>>>
>>>>
>>>>> Does LVM make the heads move around more or anything like that?
>>>>> I'm
>>>>> just thinking it would depending on what lv are on what drives. I
>>>>> dunno, just curious.
>>>>
>>>> I haven't thought about that, but my first impression is that LVM
>>>> won't
>> make any great difference. The data get stored where the data get
>> stored, if you see what I mean. How they're organised is in the
>> implementation layers. (Am I making sense? It's getting late here.)
>>>>
>>>> --
>>>>
>>>> Rgds
>>>>
>>>> Peter Linux Counter 5290, 1994-04-23
>>>>
>>>>
>>>
>>> Yea, I see the point.  I was even thinking that if LVM is on
>>> multiple
>> drives and the a lv was spanned across two or more drives, then it
>> could even be faster.  Data spanned across two or more drives could
>> result in it reading more data faster since both drives are
>> collecting data at about the same time.
>>> But then again, it depends on how the data is spread out too.  I
>>> guess it
>> is six of one and half a dozen of the other.
>> I'm not sure if LVM by itself implement striping. Most likely not
>> because LVM usually starts with 1 HD then gets additional PVs added.
>> Plus there's the possibility that the second PV has a different size.
>>
>> I might be wrong, though, since all my experience with LVM involves
>> only one drive.
>
> LVM does do striping according to the man page. I've never tried it,
> mostly because LVM is the wrong place to do that IMHO.
>
> Use RAID for that instead and leave LVM to do what it's good at -
> managing storage volumes
>
>

What I was thinking about is this.  You have two drives that is one lv.  
It has to be data stored on both drives at some point.  Example, you 
have a data base that is 500Gbs.  You have two drives that are 300Gbs 
each that are in the same lv.  Well obviously 200Gbs has to be on a 
different drive.  Isn't that striping which would would result in a 
speed increase?

Now if it is like me and is only one drive, then that won't happen.

Dale

:-)  :-)

Re: [gentoo-user] grub and what happens exactly when booting.

[Thanasis]

on 09/19/2011 11:01 AM Dale wrote the following:

> What I was thinking about is this.  You have two drives that is one lv. 
> It has to be data stored on both drives at some point.  Example, you
> have a data base that is 500Gbs.  You have two drives that are 300Gbs
> each that are in the same lv.  Well obviously 200Gbs has to be on a
> different drive.  Isn't that striping 

I think, for stripping you have to use
lvcreate with option "-I StripeSize"

Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Mon, 19 Sep 2011 03:01:32 -0500
Dale <rdalek1967@gmail.com> wrote:

> >> I'm not sure if LVM by itself implement striping. Most likely not
> >> because LVM usually starts with 1 HD then gets additional PVs
> >> added. Plus there's the possibility that the second PV has a
> >> different size.
> >>
> >> I might be wrong, though, since all my experience with LVM involves
> >> only one drive.  
> >
> > LVM does do striping according to the man page. I've never tried it,
> > mostly because LVM is the wrong place to do that IMHO.
> >
> > Use RAID for that instead and leave LVM to do what it's good at -
> > managing storage volumes
> >
> >  
> 
> What I was thinking about is this.  You have two drives that is one
> lv. It has to be data stored on both drives at some point.  Example,
> you have a data base that is 500Gbs.  You have two drives that are
> 300Gbs each that are in the same lv.  Well obviously 200Gbs has to be
> on a different drive.  Isn't that striping which would would result
> in a speed increase?
> 
> Now if it is like me and is only one drive, then that won't happen.

Think about this from a viewpoint of design.

You took two drives and put them in one big VG then assigned an LV to
the entire VG.

Now, what can you reasonably expect LVM to do with this? The obvious
answer is that PVs can be any old size and speed so LVM should just go
and do what it thinks is best. You only have one volume, there is zero
information available to the software to help it decide which PV is
better for which use, it can't look at your files on the LV and use
that to decide (LVM is clueless about fs structure and files), it
can't look at the connection type and decide to give higher priority to
Fibre connected drives in preference to USB connected drives. So the
only thing it could possibly do is maybe perhaps notice that the PVs
are the same size and maybe perhaps decide to do striping. Maybe. What
it will probably do is fill the first drive then start on the second.

Your case of two identical drives for a big database is not the usual
case for LVM, it is built to deal with VGs consisting of just about
anything. Any support it has for striping and mirroring would be
necessarily highly limited.

There is a MUCH better to do this, it's RAID which was designed to deal
with exactly this kind of thing. You know how you want those two drives
to behave, so put them in a RAID array first, set up the way you want
them. That will give you a block device that you turn into a PV, add
this single PV to a VG and make an LV from that.


-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Pandu Poluan]

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On Sep 19, 2011 2:29 PM, "Alan McKinnon" <alan.mckinnon@gmail.com> wrote:
>
> On Mon, 19 Sep 2011 13:51:03 +0700
> Pandu Poluan <pandu@poluan.info> wrote:
>
> >
> > I'm not sure if LVM by itself implement striping. Most likely not
> > because LVM usually starts with 1 HD then gets additional PVs added.
> > Plus there's the possibility that the second PV has a different size.
> >
> > I might be wrong, though, since all my experience with LVM involves
> > only one drive.
>
>
> LVM does do striping according to the man page. I've never tried it,
> mostly because LVM is the wrong place to do that IMHO.
>
> Use RAID for that instead and leave LVM to do what it's good at -
> managing storage volumes
>

Ah, thanks for the correction. Anyways, I agree with your last sentence.

Soft-RAID is always a catastrophe waiting to happen.

Rgds,

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Re: [gentoo-user] grub and what happens exactly when booting.

[Joost Roeleveld]

On Monday, September 19, 2011 03:01:32 AM Dale wrote:
> Alan McKinnon wrote:
> > On Mon, 19 Sep 2011 13:51:03 +0700
> > 
> > Pandu Poluan<pandu@poluan.info>  wrote:
> >> I'm not sure if LVM by itself implement striping. Most likely not
> >> because LVM usually starts with 1 HD then gets additional PVs added.
> >> Plus there's the possibility that the second PV has a different size.
> >> 
> >> I might be wrong, though, since all my experience with LVM involves
> >> only one drive.
> > 
> > LVM does do striping according to the man page. I've never tried it,
> > mostly because LVM is the wrong place to do that IMHO.
> > 
> > Use RAID for that instead and leave LVM to do what it's good at -
> > managing storage volumes
> 
> What I was thinking about is this.  You have two drives that is one lv.
> It has to be data stored on both drives at some point.  Example, you
> have a data base that is 500Gbs.  You have two drives that are 300Gbs
> each that are in the same lv.  Well obviously 200Gbs has to be on a
> different drive.  Isn't that striping which would would result in a
> speed increase?

I think you're using the wrong names for the different pieces.
The 2 300GB drives will be Physical Volumes (PV)
These 2 PVs are in the Volume Group (VG)
This VG has 1 LV for database.

This LV, as it's at least 500GB will have parts on both PVs (harddrives)

This will have increased performance when the data being read happens to be on 
2 physically different drives. If you just extend over 2 (or more) drives, 
this is not very likely as the first 300GB of data will still, physically, be 
on the same drive.

To spread the data more equally (eg. sequential parts will be on alternating 
drives) you have 2 options:
1) Merge the 2 drives in a single RAID0-device (for striping)
2) Tell LVM to use striping for the LV when creating it.

My personal preference would be option 1 as I agree with Alan that LVM should 
stick to managing LVs and leave striping and other options to RAID-
devices/software.

> Now if it is like me and is only one drive, then that won't happen.

With only one drive, definitely not :)

--
Joost

Re: [gentoo-user] grub and what happens exactly when booting.

[David W Noon]

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On Mon, 19 Sep 2011 09:26:16 +0200, Alan McKinnon wrote about "Re:
[gentoo-user] grub and what happens exactly when booting.":

[snip]
>LVM does do striping according to the man page. I've never tried it,
>mostly because LVM is the wrong place to do that IMHO.
>
>Use RAID for that instead and leave LVM to do what it's good at -
>managing storage volumes

But LVM and software RAID do that in the same place: the "dm" driver,
inside the kernel.  Using LVM to create stripes, when that is the only
RAID-like feature you need, eliminates the complexity of having the RAID
software installed.
-- 
Regards,

Dave  [RLU #314465]
======================================================================
dwnoon@ntlworld.com (David W Noon)
======================================================================

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Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Mon, 19 Sep 2011 15:54:52 +0700
Pandu Poluan <pandu@poluan.info> wrote:

> > LVM does do striping according to the man page. I've never tried it,
> > mostly because LVM is the wrong place to do that IMHO.
> >
> > Use RAID for that instead and leave LVM to do what it's good at -
> > managing storage volumes
> >
> 
> Ah, thanks for the correction. Anyways, I agree with your last
> sentence.
> 
> Soft-RAID is always a catastrophe waiting to happen.
> 

My experience has always been that Linux software raid gets the job
done perfectly, every time, no issues and has never failed me.

Hardware RAID is another story, especially those cheap nasty
onboard pseudo-RAID thingies. DOubly so if the name Adaptec appears
anywhere.

-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Mon, 19 Sep 2011 10:55:19 +0200
Joost Roeleveld <joost@antarean.org> wrote:

> My personal preference would be option 1 as I agree with Alan that
> LVM should stick to managing LVs and leave striping and other options
> to RAID- devices/software.

My preference is to get rid of this whole artifical
disk/block-device/partition/pv/vg/lv nonsense and have one layer that
does it all. I really don't see the point in persisting with keeping
knowledge of distinct disks all the way through the stack, all of that
should just be abstracted into "storage" that can have rules attached
where you specify how you want stuff to behave (like mirroring and
striping).

As it is, each layer is a very thin wrapper around a physical object
and we only lose that distinction when we create lvs. Even though I
understand how the whole stack works, it's still hard to visualize (5
layers!) and consumes way too much time explaining it to people. All
rather unnecessary.

I had high hopes that ZFS would take us to a new place where all that
would be possible.


-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Michael Mol]

On Mon, Sep 19, 2011 at 10:13 AM, Alan McKinnon <alan.mckinnon@gmail.com> wrote:
> On Mon, 19 Sep 2011 15:54:52 +0700
> Pandu Poluan <pandu@poluan.info> wrote:
>
>> > LVM does do striping according to the man page. I've never tried it,
>> > mostly because LVM is the wrong place to do that IMHO.
>> >
>> > Use RAID for that instead and leave LVM to do what it's good at -
>> > managing storage volumes
>> >
>>
>> Ah, thanks for the correction. Anyways, I agree with your last
>> sentence.
>>
>> Soft-RAID is always a catastrophe waiting to happen.
>>
>
> My experience has always been that Linux software raid gets the job
> done perfectly, every time, no issues and has never failed me.
>
> Hardware RAID is another story, especially those cheap nasty
> onboard pseudo-RAID thingies. DOubly so if the name Adaptec appears
> anywhere.

Seconding software raid. Looking forward to btrfs being full-featured,
though, as integrating lvm and raid functionality sanely into the
filesystem a la ZFS is going to be very, very nice.


-- 
:wq

Re: [gentoo-user] grub and what happens exactly when booting.

[Pandu Poluan]

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On Sep 19, 2011 10:05 PM, "Alan McKinnon" <alan.mckinnon@gmail.com> wrote:
>
> On Mon, 19 Sep 2011 15:54:52 +0700
> Pandu Poluan <pandu@poluan.info> wrote:
>
> > > LVM does do striping according to the man page. I've never tried it,
> > > mostly because LVM is the wrong place to do that IMHO.
> > >
> > > Use RAID for that instead and leave LVM to do what it's good at -
> > > managing storage volumes
> > >
> >
> > Ah, thanks for the correction. Anyways, I agree with your last
> > sentence.
> >
> > Soft-RAID is always a catastrophe waiting to happen.
> >
>
> My experience has always been that Linux software raid gets the job
> done perfectly, every time, no issues and has never failed me.
>
> Hardware RAID is another story, especially those cheap nasty
> onboard pseudo-RAID thingies. DOubly so if the name Adaptec appears
> anywhere.
>

Ah yes. If we're talking about entry-level RAID, then I agree; Linux's RAID
is head and shoulders above cheapo Adaptec pseudo-RAID.

But in an Enterprise setting, I trust the server box's battery-backed RAID
controller better than any software solution.

At least, in the latter case we have a 3rd party to sue ;-)

Rgds,

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Re: [gentoo-user] grub and what happens exactly when booting.

[Pandu Poluan]

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On Sep 19, 2011 10:07 PM, "Alan McKinnon" <alan.mckinnon@gmail.com> wrote:
>
> My preference is to get rid of this whole artifical
> disk/block-device/partition/pv/vg/lv nonsense and have one layer that
> does it all. I really don't see the point in persisting with keeping
> knowledge of distinct disks all the way through the stack, all of that
> should just be abstracted into "storage" that can have rules attached
> where you specify how you want stuff to behave (like mirroring and
> striping).
>
> As it is, each layer is a very thin wrapper around a physical object
> and we only lose that distinction when we create lvs. Even though I
> understand how the whole stack works, it's still hard to visualize (5
> layers!) and consumes way too much time explaining it to people. All
> rather unnecessary.
>
> I had high hopes that ZFS would take us to a new place where all that
> would be possible.
>

Sounds like you need a SAN Storage solution like NetApp or HDS :-)

Heck, OpenFiler is a surprisingly good solution; it's now being used in
production in my company's subsidiary.

Rgds,

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Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Mon, 19 Sep 2011 22:40:36 +0700
Pandu Poluan <pandu@poluan.info> wrote:

> > I had high hopes that ZFS would take us to a new place where all
> > that would be possible.
> >
> 
> Sounds like you need a SAN Storage solution like NetApp or HDS :-)

I have those options too. But the team that runs the SAN charges and
the rates are not cheap.

So far the best external storage our team has ever had is the Dell
M9000 on the ftp server. 15TB raw space, 11TB usable, connected as a
simple DAS, and it's run for years without any issues at all. 

> Heck, OpenFiler is a surprisingly good solution; it's now being used
> in production in my company's subsidiary.

A colleague is thrilled with OpenFiler, I haven't checked it out myself
yet. I might just try it out on a media server.

-- 
Alan McKinnnon
alan.mckinnon@gmail.com

Re: [gentoo-user] grub and what happens exactly when booting.

[Pandu Poluan]

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On Sep 20, 2011 3:03 AM, "Alan McKinnon" <alan.mckinnon@gmail.com> wrote:
>
> On Mon, 19 Sep 2011 22:40:36 +0700
> Pandu Poluan <pandu@poluan.info> wrote:
>
> > > I had high hopes that ZFS would take us to a new place where all
> > > that would be possible.
> > >
> >
> > Sounds like you need a SAN Storage solution like NetApp or HDS :-)
>
> I have those options too. But the team that runs the SAN charges and
> the rates are not cheap.
>

Yeah, tell me about it.

The day after we got our first NetApp array, the Finance Director demanded
to know how we were going to recoup the cost >.<

Then the next week, the company got its bacon saved when the production
database got corrupted. We quickly mount the previous hour's snapshot, and
averted an off day. Suddenly, the NetApp array became the company's most
valuable asset.

(Reading BOFH indeed opened up my team's unlimited resource of creativity
;-)  )

> So far the best external storage our team has ever had is the Dell
> M9000 on the ftp server. 15TB raw space, 11TB usable, connected as a
> simple DAS, and it's run for years without any issues at all.
>
> > Heck, OpenFiler is a surprisingly good solution; it's now being used
> > in production in my company's subsidiary.
>
> A colleague is thrilled with OpenFiler, I haven't checked it out myself
> yet. I might just try it out on a media server.
>

You should! If you want to play around first, install it as a VM.

There are some 'gotcha's, not necessarily data-corrupting bugs, but annoying
ones like: if the conditions are right, a reboot will fail to remount LVs
(simple edit to one of the scripts fixes that). And configuring it to
provide iSCSI LUNs is very... involved.

But once you get the hang of it, everything will be a breeze, just like the
... involved way of installing Gentoo :-)

As for stability, I have no complaint whatsoever.

Beside OpenFiler, you might also want to take a look at Nexenta. Similar
solution to OpenFiler (i.e., convert a server-full-of-hard-disks into a SAN
Storage), but based on OpenSolaris.

And if you do not need the utmost performance, e.g., just a never-ending
NAS, I have heard that QNAP enclosures are the act to follow.

Rgds,

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Re: [gentoo-user] grub and what happens exactly when booting.

[Alan McKinnon]

On Tue, 20 Sep 2011 07:19:18 +0700
Pandu Poluan <pandu@poluan.info> wrote:

[snip]

> > > Sounds like you need a SAN Storage solution like NetApp or HDS :-)
> >
> > I have those options too. But the team that runs the SAN charges and
> > the rates are not cheap.
> >
> 
> Yeah, tell me about it.
> 
> The day after we got our first NetApp array, the Finance Director
> demanded to know how we were going to recoup the cost >.<
> 
> Then the next week, the company got its bacon saved when the
> production database got corrupted. We quickly mount the previous
> hour's snapshot, and averted an off day. Suddenly, the NetApp array
> became the company's most valuable asset.
> 
> (Reading BOFH indeed opened up my team's unlimited resource of
> creativity ;-)  )

Ah, bean counters. Those fellows have an annoying habit of asking:

"Please tell me why I must spend a trifling amount of money (in
comparison to my own wages) on something that protects our major asset?"

I have found that cron and at provides the way to demonstrate exactly
why one must spend that money.

-- 
Alan McKinnnon
alan.mckinnon@gmail.com