[gentoo-user] where did lvm installation guide go?

[gentoo-user] where did lvm installation guide go?

[gottlieb]

I want to reinstall an old system to have combined root+usr.

I have always used an lvm installation guide that was a "companion" to
the handbook.  That is it would tell you how to augment each handbook
installation chapter for lvm (actually lvm2).

I can't find this documentation now on gentoo.org.  There is a big wiki
page, but that is different as are daniel's 2-volume "learning linux
lvm".

The closest I found is the raid+lvm quick install guide, but i would be
happier with the one I have used often in the past.

Any clues (I am emotionally prepared to learn that it is right there on
the installation web page, but my eyes and search commands are
deficient).

thanks,
allan

[gentoo-user] Re: where did lvm installation guide go?

[James]

 <gottlieb <at> nyu.edu> writes:


> I can't find this documentation now on gentoo.org.  There is a big wiki
> page, but that is different as are daniel's 2-volume "learning linux
> lvm".

Gentoo is massively reorganizing documentation. The old
"system" was arcane, and a fools errand to try to use.
A Few stalwarts resisted change for a long time. Gentoo-doc
teams needs lots of volunteers.

You most accurate resource  is to communicate with the
gentoo-doc team directly. At the least, old version
of deprecated documents might still be around?

Good-Hunting,
James

gentoo-doc@lists.gentoo.org


On 07/24/13 16:59, Sven Vermeulen wrote:
> Hi guys
> 
> If you're following commits, you'll notice that I'm in the process of moving
> documents from the www.gentoo.org/doc/en location to the Gentoo wiki.
> Currently, I'm basing myself on the bugs we have open for the documents that
> haven't been touched in a while, or that are for guides that aren't fully
> maintained.
> 
> Once that is done, I will move the guides that haven't been touched in a
> while as well (starting last edit 2003, then 2004, etc.) and those that I am
> the main author for (as I'll be doing my edits in the Gentoo wiki).
> 
> The translation support in the Gentoo Wiki is working quite well imo
> (correct me if I'm wrong) as it supports translations almost simultaneously
> by multiple translators. Also, the process for editing is "now" rather than
> having people become potential recruitees first.
> 
> During the majority of documentation moves, I will probably update the main
> site link from the Gentoo site (towards /doc/en/list.xml) towards a page (or
> category) that presents all documents on the wiki that are marked as
> translatable. Personally, I think only those documents that are well
> reviewed and edited should be marked as translatable, which is why I haven't
> gone through the entire wiki site marking all articles as translatable.

Re: [gentoo-user] where did lvm installation guide go?

[Canek Peláez Valdés]

On Thu, Aug 29, 2013 at 10:47 AM,  <gottlieb@nyu.edu> wrote:
> I want to reinstall an old system to have combined root+usr.
>
> I have always used an lvm installation guide that was a "companion" to
> the handbook.  That is it would tell you how to augment each handbook
> installation chapter for lvm (actually lvm2).
>
> I can't find this documentation now on gentoo.org.  There is a big wiki
> page, but that is different as are daniel's 2-volume "learning linux
> lvm".
>
> The closest I found is the raid+lvm quick install guide, but i would be
> happier with the one I have used often in the past.
>
> Any clues (I am emotionally prepared to learn that it is right there on
> the installation web page, but my eyes and search commands are
> deficient).

As James said, the docs are being reorganized. However, I did a
systemd+LVM installation (just because I was getting tired of not
knowing what the fuss was all about), and (in my experience) there are
almost no changes from the regular installation in the handbook.

I put everything in LVM (/, /boot, everything). From my notes, the
only changes are:

From the livecd:
1. Use partitions, not whole disks (GRUB2 got confused when I tried to
use whole disks).
2. Set the partition type as LVM (8e in fdisk).
3. Create the Physical Volume, the Volume Group, and the Logical
Volumes as desired.
4. Continue the normal installation, just using /dev/vg0/lvolX (or
whatever names you choose).

After the chroot and emerging the kernel package:
1. Se the LVM options in the kernel. Compile, install it.
2. Emerge systemd.
3. Emerge dracut (USE="device-mapper", DRACUT_MODULES="systemd lvm", at least).
4. Set add_dracutmodules="systemd" in /etc/dracut.conf.
5. Weirdly, set lvmconf="no" in /etc/dracut.conf. I didn't even
touched /etc/lvm/lvm.conf, so I think leaving it out makes dracut to
autoconfigure it. If I put lvmconf="yes", the boot hangs. Didn't
investigated why.
6. Emerge GRUB2 (USE="device-mapper mount"); I don't know if GRUB
works with LVM, but GRUB2 does, so I used that.
7. Set GRUB_PRELOAD_MODULES="lvm",
GRUB_CMDLINE_LINUX="init=/usr/lib/systemd/systemd", in
/etc/default/grub.
8. Generate initramfs, generate /boot/grub2/grub.cfg, install GRUB2
with grub2-install.
9. Reboot. Everything works.

GRUB2 handles LVM just fine, I believe, but my LVM setup was dead
simple (the VG was just the only partition of all my disks).
dracut+systemd takes care of everything else; I didn't even had to do
something special in fstab, since I used labels.

To extend/reduce your Logical Volumes you will need a livecd, or a
more complex initramfs, though.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México

Re: [gentoo-user] Re: where did lvm installation guide go?

[gottlieb]

On Thu, Aug 29 2013, James wrote:

>  <gottlieb <at> nyu.edu> writes:
>
>
>> I can't find this documentation now on gentoo.org.  There is a big wiki
>> page, but that is different as are daniel's 2-volume "learning linux
>> lvm".
>
> Gentoo is massively reorganizing documentation. The old
> "system" was arcane, and a fools errand to try to use.
> A Few stalwarts resisted change for a long time. Gentoo-doc
> teams needs lots of volunteers.

I should volunteer.

> You most accurate resource  is to communicate with the
> gentoo-doc team directly. At the least, old version
> of deprecated documents might still be around?
>
> Good-Hunting,
> James

Thanks,
allan

Re: [gentoo-user] where did lvm installation guide go?

[gottlieb]

On Thu, Aug 29 2013, Canek Peláez Valdés wrote:

> As James said, the docs are being reorganized. However, I did a
> systemd+LVM installation (just because I was getting tired of not
> knowing what the fuss was all about), and (in my experience) there are
> almost no changes from the regular installation in the handbook.
>
> I put everything in LVM (/, /boot, everything).

I am not so ambitious.  /+/boot+/usr one ext4 partition not on lvm

> From my notes, the only changes are:
>
>>From the livecd:
> 1. Use partitions, not whole disks (GRUB2 got confused when I tried to
> use whole disks).
> 2. Set the partition type as LVM (8e in fdisk).
> 3. Create the Physical Volume, the Volume Group, and the Logical
> Volumes as desired.
> 4. Continue the normal installation, just using /dev/vg0/lvolX (or
> whatever names you choose).

There is a little more (activating or something the LVs) especially if
you shutdown in the middle of the installation and resume it later.

> After the chroot and emerging the kernel package:
> 1. Se the LVM options in the kernel. Compile, install it.
> 2. Emerge systemd.
> 3. Emerge dracut (USE="device-mapper", DRACUT_MODULES="systemd lvm", at least).
> 4. Set add_dracutmodules="systemd" in /etc/dracut.conf.
> 5. Weirdly, set lvmconf="no" in /etc/dracut.conf. I didn't even
> touched /etc/lvm/lvm.conf, so I think leaving it out makes dracut to
> autoconfigure it. If I put lvmconf="yes", the boot hangs. Didn't
> investigated why.
> 6. Emerge GRUB2 (USE="device-mapper mount"); I don't know if GRUB
> works with LVM, but GRUB2 does, so I used that.
> 7. Set GRUB_PRELOAD_MODULES="lvm",
> GRUB_CMDLINE_LINUX="init=/usr/lib/systemd/systemd", in
> /etc/default/grub.
> 8. Generate initramfs, generate /boot/grub2/grub.cfg, install GRUB2
> with grub2-install.
> 9. Reboot. Everything works.
>
> GRUB2 handles LVM just fine, I believe, but my LVM setup was dead
> simple (the VG was just the only partition of all my disks).
> dracut+systemd takes care of everything else; I didn't even had to do
> something special in fstab, since I used labels.
>
> To extend/reduce your Logical Volumes you will need a livecd, or a
> more complex initramfs, though.
>
> Regards.

I have experience with LVM, but not systemd or dracut or initramfs

* both grub and grub2 support lvm
* Never did 2,3,4,5,7, or the initramfs part of 8

My goal is to have this system (an older laptop) setup like my current
laptop (grub2, openrc, root+/usr, etc).  Then I will convert OLD to
systemd.  Once I have done this and moved my work from CURRENT to OLD, I
will convert CURRENT to systemd and move back.

thanks to you and james for your helpful comments.

allan

Re: [gentoo-user] where did lvm installation guide go?

[Canek Peláez Valdés]

On Thu, Aug 29, 2013 at 4:19 PM,  <gottlieb@nyu.edu> wrote:
> On Thu, Aug 29 2013, Canek Peláez Valdés wrote:
>
>> As James said, the docs are being reorganized. However, I did a
>> systemd+LVM installation (just because I was getting tired of not
>> knowing what the fuss was all about), and (in my experience) there are
>> almost no changes from the regular installation in the handbook.
>>
>> I put everything in LVM (/, /boot, everything).
>
> I am not so ambitious.  /+/boot+/usr one ext4 partition not on lvm
>
>> From my notes, the only changes are:
>>
>>>From the livecd:
>> 1. Use partitions, not whole disks (GRUB2 got confused when I tried to
>> use whole disks).
>> 2. Set the partition type as LVM (8e in fdisk).
>> 3. Create the Physical Volume, the Volume Group, and the Logical
>> Volumes as desired.
>> 4. Continue the normal installation, just using /dev/vg0/lvolX (or
>> whatever names you choose).
>
> There is a little more (activating or something the LVs) especially if
> you shutdown in the middle of the installation and resume it later.
>
>> After the chroot and emerging the kernel package:
>> 1. Se the LVM options in the kernel. Compile, install it.
>> 2. Emerge systemd.
>> 3. Emerge dracut (USE="device-mapper", DRACUT_MODULES="systemd lvm", at least).
>> 4. Set add_dracutmodules="systemd" in /etc/dracut.conf.
>> 5. Weirdly, set lvmconf="no" in /etc/dracut.conf. I didn't even
>> touched /etc/lvm/lvm.conf, so I think leaving it out makes dracut to
>> autoconfigure it. If I put lvmconf="yes", the boot hangs. Didn't
>> investigated why.
>> 6. Emerge GRUB2 (USE="device-mapper mount"); I don't know if GRUB
>> works with LVM, but GRUB2 does, so I used that.
>> 7. Set GRUB_PRELOAD_MODULES="lvm",
>> GRUB_CMDLINE_LINUX="init=/usr/lib/systemd/systemd", in
>> /etc/default/grub.
>> 8. Generate initramfs, generate /boot/grub2/grub.cfg, install GRUB2
>> with grub2-install.
>> 9. Reboot. Everything works.
>>
>> GRUB2 handles LVM just fine, I believe, but my LVM setup was dead
>> simple (the VG was just the only partition of all my disks).
>> dracut+systemd takes care of everything else; I didn't even had to do
>> something special in fstab, since I used labels.
>>
>> To extend/reduce your Logical Volumes you will need a livecd, or a
>> more complex initramfs, though.
>>
>> Regards.
>
> I have experience with LVM, but not systemd or dracut or initramfs
>
> * both grub and grub2 support lvm

Does GRUB legacy handles /boot in LVM? I haven't tried that yet.

> * Never did 2,3,4,5,7, or the initramfs part of 8
>
> My goal is to have this system (an older laptop) setup like my current
> laptop (grub2, openrc, root+/usr, etc).  Then I will convert OLD to
> systemd.  Once I have done this and moved my work from CURRENT to OLD, I
> will convert CURRENT to systemd and move back.

That sounds complex.

> thanks to you and james for your helpful comments.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México

Re: [gentoo-user] where did lvm installation guide go?

[gottlieb]

On Thu, Aug 29 2013, Canek Peláez Valdés wrote:

> On Thu, Aug 29, 2013 at 4:19 PM,  <gottlieb@nyu.edu> wrote:
>>
>> I have experience with LVM, but not systemd or dracut or initramfs
>>
>> * both grub and grub2 support lvm
>
> Does GRUB legacy handles /boot in LVM? I haven't tried that yet.

That I don't know.  I believe the LVM "companion manual" that I am
seeking and that I used for previous installs advised against /boot on
lvm (probably also /lib and others).  Perhaps this was simply reflecting
no initramfs.  Hence any grub issue with /boot on lvm didn't arise.

allan

Re: [gentoo-user] where did lvm installation guide go?

[Canek Peláez Valdés]

On Thu, Aug 29, 2013 at 8:45 PM,  <gottlieb@nyu.edu> wrote:
> On Thu, Aug 29 2013, Canek Peláez Valdés wrote:
>
>> On Thu, Aug 29, 2013 at 4:19 PM,  <gottlieb@nyu.edu> wrote:
>>>
>>> I have experience with LVM, but not systemd or dracut or initramfs
>>>
>>> * both grub and grub2 support lvm
>>
>> Does GRUB legacy handles /boot in LVM? I haven't tried that yet.
>
> That I don't know.  I believe the LVM "companion manual" that I am
> seeking and that I used for previous installs advised against /boot on
> lvm (probably also /lib and others).  Perhaps this was simply reflecting
> no initramfs.  Hence any grub issue with /boot on lvm didn't arise.

I believe is orthogonal to an initramfs. The initramfs lives in /boot,
and if the boot loader (LILO, GRUB, GRUB2) cannot mount /boot, then
there is no initramfs. That's why GRUB2 is so damn big (it implements
LVM among other things, or at least the minimal to mount partitions
read only), and why some people are pushing for "Linux to boot Linux",
sometimes called /firstboot.

GRUB2 can mount my /boot inside LVM. Perhaps with UEFI all this will
become irrelevant.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México

Re: [gentoo-user] where did lvm installation guide go?

[J. Roeleveld]

[-- Attachment #1: Type: text/plain, Size: 974 bytes --]

gottlieb@nyu.edu wrote:
>I want to reinstall an old system to have combined root+usr.
>
>I have always used an lvm installation guide that was a "companion" to
>the handbook.  That is it would tell you how to augment each handbook
>installation chapter for lvm (actually lvm2).
>
>I can't find this documentation now on gentoo.org.  There is a big wiki
>page, but that is different as are daniel's 2-volume "learning linux
>lvm".
>
>The closest I found is the raid+lvm quick install guide, but i would be
>happier with the one I have used often in the past.
>
>Any clues (I am emotionally prepared to learn that it is right there on
>the installation web page, but my eyes and search commands are
>deficient).
>
>thanks,
>allan

Allan,

Use the raid+LVM guide and skip all the raid steps.

--
Joost
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Re: [gentoo-user] where did lvm installation guide go?

[J. Roeleveld]

[-- Attachment #1: Type: text/plain, Size: 3179 bytes --]

"Canek Peláez Valdés" <caneko@gmail.com> wrote:
>On Thu, Aug 29, 2013 at 10:47 AM,  <gottlieb@nyu.edu> wrote:
>> I want to reinstall an old system to have combined root+usr.
>>
>> I have always used an lvm installation guide that was a "companion"
>to
>> the handbook.  That is it would tell you how to augment each handbook
>> installation chapter for lvm (actually lvm2).
>>
>> I can't find this documentation now on gentoo.org.  There is a big
>wiki
>> page, but that is different as are daniel's 2-volume "learning linux
>> lvm".
>>
>> The closest I found is the raid+lvm quick install guide, but i would
>be
>> happier with the one I have used often in the past.
>>
>> Any clues (I am emotionally prepared to learn that it is right there
>on
>> the installation web page, but my eyes and search commands are
>> deficient).
>
>As James said, the docs are being reorganized. However, I did a
>systemd+LVM installation (just because I was getting tired of not
>knowing what the fuss was all about), and (in my experience) there are
>almost no changes from the regular installation in the handbook.
>
>I put everything in LVM (/, /boot, everything). From my notes, the
>only changes are:
>
>From the livecd:
>1. Use partitions, not whole disks (GRUB2 got confused when I tried to
>use whole disks).
>2. Set the partition type as LVM (8e in fdisk).
>3. Create the Physical Volume, the Volume Group, and the Logical
>Volumes as desired.
>4. Continue the normal installation, just using /dev/vg0/lvolX (or
>whatever names you choose).
>
>After the chroot and emerging the kernel package:
>1. Se the LVM options in the kernel. Compile, install it.
>2. Emerge systemd.
>3. Emerge dracut (USE="device-mapper", DRACUT_MODULES="systemd lvm", at
>least).
>4. Set add_dracutmodules="systemd" in /etc/dracut.conf.
>5. Weirdly, set lvmconf="no" in /etc/dracut.conf. I didn't even
>touched /etc/lvm/lvm.conf, so I think leaving it out makes dracut to
>autoconfigure it. If I put lvmconf="yes", the boot hangs. Didn't
>investigated why.
>6. Emerge GRUB2 (USE="device-mapper mount"); I don't know if GRUB
>works with LVM, but GRUB2 does, so I used that.
>7. Set GRUB_PRELOAD_MODULES="lvm",
>GRUB_CMDLINE_LINUX="init=/usr/lib/systemd/systemd", in
>/etc/default/grub.
>8. Generate initramfs, generate /boot/grub2/grub.cfg, install GRUB2
>with grub2-install.
>9. Reboot. Everything works.
>
>GRUB2 handles LVM just fine, I believe, but my LVM setup was dead
>simple (the VG was just the only partition of all my disks).
>dracut+systemd takes care of everything else; I didn't even had to do
>something special in fstab, since I used labels.
>
>To extend/reduce your Logical Volumes you will need a livecd, or a
>more complex initramfs, though.
>
>Regards.

Canek,

LVs can be resized while the system is running. It also depends on the actual filesystem, but extending can be done online with all filesystems I am aware of.
Shrinking is not possible with all.

--
Joost
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Re: [gentoo-user] where did lvm installation guide go?

[J. Roeleveld]

[-- Attachment #1: Type: text/plain, Size: 3179 bytes --]

"Canek Peláez Valdés" <caneko@gmail.com> wrote:
>On Thu, Aug 29, 2013 at 10:47 AM,  <gottlieb@nyu.edu> wrote:
>> I want to reinstall an old system to have combined root+usr.
>>
>> I have always used an lvm installation guide that was a "companion"
>to
>> the handbook.  That is it would tell you how to augment each handbook
>> installation chapter for lvm (actually lvm2).
>>
>> I can't find this documentation now on gentoo.org.  There is a big
>wiki
>> page, but that is different as are daniel's 2-volume "learning linux
>> lvm".
>>
>> The closest I found is the raid+lvm quick install guide, but i would
>be
>> happier with the one I have used often in the past.
>>
>> Any clues (I am emotionally prepared to learn that it is right there
>on
>> the installation web page, but my eyes and search commands are
>> deficient).
>
>As James said, the docs are being reorganized. However, I did a
>systemd+LVM installation (just because I was getting tired of not
>knowing what the fuss was all about), and (in my experience) there are
>almost no changes from the regular installation in the handbook.
>
>I put everything in LVM (/, /boot, everything). From my notes, the
>only changes are:
>
>From the livecd:
>1. Use partitions, not whole disks (GRUB2 got confused when I tried to
>use whole disks).
>2. Set the partition type as LVM (8e in fdisk).
>3. Create the Physical Volume, the Volume Group, and the Logical
>Volumes as desired.
>4. Continue the normal installation, just using /dev/vg0/lvolX (or
>whatever names you choose).
>
>After the chroot and emerging the kernel package:
>1. Se the LVM options in the kernel. Compile, install it.
>2. Emerge systemd.
>3. Emerge dracut (USE="device-mapper", DRACUT_MODULES="systemd lvm", at
>least).
>4. Set add_dracutmodules="systemd" in /etc/dracut.conf.
>5. Weirdly, set lvmconf="no" in /etc/dracut.conf. I didn't even
>touched /etc/lvm/lvm.conf, so I think leaving it out makes dracut to
>autoconfigure it. If I put lvmconf="yes", the boot hangs. Didn't
>investigated why.
>6. Emerge GRUB2 (USE="device-mapper mount"); I don't know if GRUB
>works with LVM, but GRUB2 does, so I used that.
>7. Set GRUB_PRELOAD_MODULES="lvm",
>GRUB_CMDLINE_LINUX="init=/usr/lib/systemd/systemd", in
>/etc/default/grub.
>8. Generate initramfs, generate /boot/grub2/grub.cfg, install GRUB2
>with grub2-install.
>9. Reboot. Everything works.
>
>GRUB2 handles LVM just fine, I believe, but my LVM setup was dead
>simple (the VG was just the only partition of all my disks).
>dracut+systemd takes care of everything else; I didn't even had to do
>something special in fstab, since I used labels.
>
>To extend/reduce your Logical Volumes you will need a livecd, or a
>more complex initramfs, though.
>
>Regards.

Canek,

LVs can be resized while the system is running. It also depends on the actual filesystem, but extending can be done online with all filesystems I am aware of.
Shrinking is not possible with all.

--
Joost
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Re: [gentoo-user] where did lvm installation guide go?

[J. Roeleveld]

[-- Attachment #1: Type: text/plain, Size: 990 bytes --]

gottlieb@nyu.edu wrote:
>On Thu, Aug 29 2013, Canek Peláez Valdés wrote:
>
>> On Thu, Aug 29, 2013 at 4:19 PM,  <gottlieb@nyu.edu> wrote:
>>>
>>> I have experience with LVM, but not systemd or dracut or initramfs
>>>
>>> * both grub and grub2 support lvm
>>
>> Does GRUB legacy handles /boot in LVM? I haven't tried that yet.
>
>That I don't know.  I believe the LVM "companion manual" that I am
>seeking and that I used for previous installs advised against /boot on
>lvm (probably also /lib and others).  Perhaps this was simply
>reflecting
>no initramfs.  Hence any grub issue with /boot on lvm didn't arise.
>
>allan

No.

Grub legacy does not support LVM for the /boot.
That's why I have it there.

UEFI only understands FAT. Which means you need to have a boot partition outside of LVM for that.

--
Joost
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Re: [gentoo-user] where did lvm installation guide go?

[Canek Peláez Valdés]

On Fri, Aug 30, 2013 at 12:21 AM, J. Roeleveld <joost@antarean.org> wrote:
> gottlieb@nyu.edu wrote:
>>On Thu, Aug 29 2013, Canek Peláez Valdés wrote:
>>
>>> On Thu, Aug 29, 2013 at 4:19 PM, <gottlieb@nyu.edu> wrote:
>>>>
>>>> I have experience with LVM, but not systemd or dracut or initramfs
>>>>
>>>> * both grub and grub2 support lvm
>>>
>>> Does GRUB legacy handles /boot in LVM? I haven't tried that yet.
>>
>>That I don't know. I believe the LVM "companion manual" that I am
>>seeking and that I used for previous installs advised against /boot on
>>lvm (probably also /lib and others). Perhaps this was simply
>>reflecting
>>no initramfs. Hence any grub issue with /boot on lvm didn't arise.
>>
>>allan
>
> No.
>
> Grub legacy does not support LVM for the /boot.
> That's why I have it there.
>
> UEFI only understands FAT. Which means you need to have a boot partition
> outside of LVM for that.

Good to know, thanks. Another reason not to use LVM I guess.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México

Re: [gentoo-user] where did lvm installation guide go?

[Alan McKinnon]

On 30/08/2013 03:45, gottlieb@nyu.edu wrote:
> On Thu, Aug 29 2013, Canek Peláez Valdés wrote:
> 
>> On Thu, Aug 29, 2013 at 4:19 PM,  <gottlieb@nyu.edu> wrote:
>>>
>>> I have experience with LVM, but not systemd or dracut or initramfs
>>>
>>> * both grub and grub2 support lvm
>>
>> Does GRUB legacy handles /boot in LVM? I haven't tried that yet.
> 
> That I don't know.  I believe the LVM "companion manual" that I am
> seeking and that I used for previous installs advised against /boot on
> lvm (probably also /lib and others).  Perhaps this was simply reflecting
> no initramfs.  Hence any grub issue with /boot on lvm didn't arise.

I believe this is correct

grub-legacy never did directly support reading lvm volumes,
you must use an initramfs


-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] where did lvm installation guide go?

[Alan McKinnon]

On 30/08/2013 07:36, Canek Peláez Valdés wrote:
> On Fri, Aug 30, 2013 at 12:21 AM, J. Roeleveld <joost@antarean.org> wrote:
>> gottlieb@nyu.edu wrote:
>>> On Thu, Aug 29 2013, Canek Peláez Valdés wrote:
>>>
>>>> On Thu, Aug 29, 2013 at 4:19 PM, <gottlieb@nyu.edu> wrote:
>>>>>
>>>>> I have experience with LVM, but not systemd or dracut or initramfs
>>>>>
>>>>> * both grub and grub2 support lvm
>>>>
>>>> Does GRUB legacy handles /boot in LVM? I haven't tried that yet.
>>>
>>> That I don't know. I believe the LVM "companion manual" that I am
>>> seeking and that I used for previous installs advised against /boot on
>>> lvm (probably also /lib and others). Perhaps this was simply
>>> reflecting
>>> no initramfs. Hence any grub issue with /boot on lvm didn't arise.
>>>
>>> allan
>>
>> No.
>>
>> Grub legacy does not support LVM for the /boot.
>> That's why I have it there.
>>
>> UEFI only understands FAT. Which means you need to have a boot partition
>> outside of LVM for that.
> 
> Good to know, thanks. Another reason not to use LVM I guess.

Why not use LVM?

Yes, it is some added complexity you need to understand but it stays out
of your way till you need it, doesn't affect disk efficiency in any
significant way and just works. When you need the services it offers
they are there and until then just use mkfs and mount the block device
it offers.

Unless you have all your filesystems part of / itself, you run the risk
of hitting hard limits rapidly and LVM gives you a proper way to deal
with that, unlike using rigid partitions directly. I see a small amount
of new code to understand followed by huge benefits.

The best way to deal with this actual issue is the ZFS/btrfs approach
but those aren't usable for the masses yet, whereas LVM is.


-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] where did lvm installation guide go?

[Alan McKinnon]

On 30/08/2013 07:21, J. Roeleveld wrote:
> Canek,
> 
> LVs can be resized while the system is running. It also depends on the
> actual filesystem, but extending can be done online with all filesystems
> I am aware of.
> Shrinking is not possible with all.

no fs can be reduced whilst mounted, most especially the inode based ones

This makes reducing / somewhat tricky as requires system downtime.
The usual approach sysadmins use is to estimate size conservatively and
make them larger as needed (effectively avoiding reducing any as much as
possible).

-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] where did lvm installation guide go?

[Dale]

Alan McKinnon wrote:
> On 30/08/2013 07:36, Canek Peláez Valdés wrote:
>> On Fri, Aug 30, 2013 at 12:21 AM, J. Roeleveld <joost@antarean.org> wrote:
>>> No. Grub legacy does not support LVM for the /boot. That's why I
>>> have it there. UEFI only understands FAT. Which means you need to
>>> have a boot partition outside of LVM for that. 
>> Good to know, thanks. Another reason not to use LVM I guess.
> Why not use LVM?
>
> Yes, it is some added complexity you need to understand but it stays out
> of your way till you need it, doesn't affect disk efficiency in any
> significant way and just works. When you need the services it offers
> they are there and until then just use mkfs and mount the block device
> it offers.
>
> Unless you have all your filesystems part of / itself, you run the risk
> of hitting hard limits rapidly and LVM gives you a proper way to deal
> with that, unlike using rigid partitions directly. I see a small amount
> of new code to understand followed by huge benefits.
>
> The best way to deal with this actual issue is the ZFS/btrfs approach
> but those aren't usable for the masses yet, whereas LVM is.
>
>

OP, I been using LVM for everything but /boot and / for a while now.  I
have to say, it is really really nice to have.  When something needs
more space, it is easily resized and life carries on. 

Just pick the places where you can use it without adding any other
complexities you don't want.  Example, don't want a init thingy, put /
on a regular partition and normal file system, just make sure you won't
fill it up for a very long time.  Of course /boot has to be on a regular
file system too. 

Hope that helps.

Dale

:-)  :-) 

-- 
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!

Re: [gentoo-user] where did lvm installation guide go?

[Dale]

Alan McKinnon wrote:
> On 30/08/2013 03:45, gottlieb@nyu.edu wrote:
>> On Thu, Aug 29 2013, Canek Peláez Valdés wrote:
>>
>>> On Thu, Aug 29, 2013 at 4:19 PM,  <gottlieb@nyu.edu> wrote:
>>>> I have experience with LVM, but not systemd or dracut or initramfs
>>>>
>>>> * both grub and grub2 support lvm
>>> Does GRUB legacy handles /boot in LVM? I haven't tried that yet.
>> That I don't know.  I believe the LVM "companion manual" that I am
>> seeking and that I used for previous installs advised against /boot on
>> lvm (probably also /lib and others).  Perhaps this was simply reflecting
>> no initramfs.  Hence any grub issue with /boot on lvm didn't arise.
> I believe this is correct
>
> grub-legacy never did directly support reading lvm volumes,
> you must use an initramfs
>
>

That is my understanding as well.  I switched from it a while ago but
almost certain it only supports regular file systems like ext2, ext4 etc
etc.

Dale

:-)  :-) 

-- 
I am only responsible for what I said ... Not for what you understood or how you interpreted my words!

Re: [gentoo-user] where did lvm installation guide go?

[Tanstaafl]

On 2013-08-30 3:16 AM, Dale <rdalek1967@gmail.com> wrote:
> Example, don't want a init thingy, put / on a regular partition and
> normal file system, just make sure you won't fill it up for a very
> long time. Of course /boot has to be on a regular file system too.

Well, apparently this now includes /usr, as from what I gleaned from the 
earlier thread, there is no guarantee even eudev will continue to 
support separate /usr partition in future (since gentoo council has 
formally voted to NOT support it without an initramfs)...

Re: [gentoo-user] where did lvm installation guide go?

[Canek Peláez Valdés]

On Fri, Aug 30, 2013 at 1:10 AM, Alan McKinnon <alan.mckinnon@gmail.com> wrote:
> On 30/08/2013 07:36, Canek Peláez Valdés wrote:
>> On Fri, Aug 30, 2013 at 12:21 AM, J. Roeleveld <joost@antarean.org> wrote:
>>> gottlieb@nyu.edu wrote:
>>>> On Thu, Aug 29 2013, Canek Peláez Valdés wrote:
>>>>
>>>>> On Thu, Aug 29, 2013 at 4:19 PM, <gottlieb@nyu.edu> wrote:
>>>>>>
>>>>>> I have experience with LVM, but not systemd or dracut or initramfs
>>>>>>
>>>>>> * both grub and grub2 support lvm
>>>>>
>>>>> Does GRUB legacy handles /boot in LVM? I haven't tried that yet.
>>>>
>>>> That I don't know. I believe the LVM "companion manual" that I am
>>>> seeking and that I used for previous installs advised against /boot on
>>>> lvm (probably also /lib and others). Perhaps this was simply
>>>> reflecting
>>>> no initramfs. Hence any grub issue with /boot on lvm didn't arise.
>>>>
>>>> allan
>>>
>>> No.
>>>
>>> Grub legacy does not support LVM for the /boot.
>>> That's why I have it there.
>>>
>>> UEFI only understands FAT. Which means you need to have a boot partition
>>> outside of LVM for that.
>>
>> Good to know, thanks. Another reason not to use LVM I guess.
>
> Why not use LVM?

I just don't see the point. I have never used it, and now that I have
a test system, I don't see any advantage for my particular use cases.

> Yes, it is some added complexity you need to understand but it stays out
> of your way till you need it, doesn't affect disk efficiency in any
> significant way and just works. When you need the services it offers
> they are there and until then just use mkfs and mount the block device
> it offers.

My point exactly; I have never needed its services in 18 years using
Linux (servers and workstation). Again, in my use cases.

> Unless you have all your filesystems part of / itself, you run the risk
> of hitting hard limits rapidly and LVM gives you a proper way to deal
> with that, unlike using rigid partitions directly. I see a small amount
> of new code to understand followed by huge benefits.

I understand the code all right, as I commented to Allan I had no
problems installing a systemd+LVM machine (with even /boot in LVM). I
just don't see the benefits (in my use cases).

> The best way to deal with this actual issue is the ZFS/btrfs approach
> but those aren't usable for the masses yet, whereas LVM is.

btrfs sounds cool (specially in SSD), but I'm also waiting for it to
be stable enough.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México

Re: [gentoo-user] where did lvm installation guide go?

[Canek Peláez Valdés]

On Fri, Aug 30, 2013 at 9:05 AM, Tanstaafl <tanstaafl@libertytrek.org> wrote:
> On 2013-08-30 3:16 AM, Dale <rdalek1967@gmail.com> wrote:
>>
>> Example, don't want a init thingy, put / on a regular partition and
>> normal file system, just make sure you won't fill it up for a very
>> long time. Of course /boot has to be on a regular file system too.
>
>
> Well, apparently this now includes /usr, as from what I gleaned from the
> earlier thread, there is no guarantee even eudev will continue to support
> separate /usr partition in future (since gentoo council has formally voted
> to NOT support it without an initramfs)...

udev/eudev has nothing to do with it. It's the init systems (as in
both systemd and OpenRC) the ones that are pushing/have pushed for
dropping support for it. In Gentoo, the move is being championed by
William Hubs:

http://thread.gmane.org/gmane.linux.gentoo.project/2946

He's the OpenRC maintainer. NOBODY who has actually worked on the
problem wants to support a separate /usr without an initramfs, because
it makes no sense.

So it doesn't matter if you use udev, eudev, mdev or even a static
/dev directory; no init system wants to support a separate /usr
without an initramfs.

And for a good reason: is braindead.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México

Re: [gentoo-user] where did lvm installation guide go?

[Tanstaafl]

On 2013-08-30 10:28 AM, Canek Peláez Valdés <caneko@gmail.com> wrote:
> udev/eudev has nothing to do with it. It's the init systems (as in
> both systemd and OpenRC) the ones that are pushing/have pushed for
> dropping support for it. In Gentoo, the move is being championed by
> William Hubs:
>
> http://thread.gmane.org/gmane.linux.gentoo.project/2946
>
> He's the OpenRC maintainer. NOBODY who has actually worked on the
> problem wants to support a separate /usr without an initramfs, because
> it makes no sense.

Please stop making such false statements.

It only makes no sense because of *other* decisions being made that want 
to force files critical to booting to be placed into /usr.

There is no *philosophical* reason that it 'makes no sense.

> So it doesn't matter if you use udev, eudev, mdev or even a static
> /dev directory; no init system wants to support a separate /usr
> without an initramfs.

Just fyi... the *only* problem that I have with this is that I have an 
*existing* system that has a separate /usr, and it only has that 
separate /usr because when I followed the original gentoo installation 
handbook back in 2003 or so, it actually had a separate /usr in the 
example directory structure layout, so I thought it was the official 
gentoo *recommendation* to do it that way.

If I wasn't in this predicament, I'd just make a mental note to never 
install /usr to a separate partition and be done with it.

> And for a good reason: is braindead.

Again - it is only braindead if you accept the basic premise that it 
'makes sense' to put files critical to the boot process into /usr.

Personally, I think it only 'makes sense' to put files critical to the 
boot process into <gasp!> /boot.

Re: [gentoo-user] where did lvm installation guide go?

[Alan McKinnon]

On 30/08/2013 16:37, Tanstaafl wrote:
>> And for a good reason: is braindead.
> 
> Again - it is only braindead if you accept the basic premise that it
> 'makes sense' to put files critical to the boot process into /usr.
> 
> Personally, I think it only 'makes sense' to put files critical to the
> boot process into <gasp!> /boot.


It's not the boot process. It's the startup-to-early-init process.

Or put another way, the entire start process up to the point where all
of /usr is reliably available.

"boot" is used here as very loose slang

-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] where did lvm installation guide go?

[Canek Peláez Valdés]

On Fri, Aug 30, 2013 at 9:37 AM, Tanstaafl <tanstaafl@libertytrek.org> wrote:
> On 2013-08-30 10:28 AM, Canek Peláez Valdés <caneko@gmail.com> wrote:
>>
>> udev/eudev has nothing to do with it. It's the init systems (as in
>> both systemd and OpenRC) the ones that are pushing/have pushed for
>> dropping support for it. In Gentoo, the move is being championed by
>> William Hubs:
>>
>> http://thread.gmane.org/gmane.linux.gentoo.project/2946
>>
>> He's the OpenRC maintainer. NOBODY who has actually worked on the
>> problem wants to support a separate /usr without an initramfs, because
>> it makes no sense.
>
>
> Please stop making such false statements.
>
> It only makes no sense because of *other* decisions being made that want to
> force files critical to booting to be placed into /usr.
>
> There is no *philosophical* reason that it 'makes no sense.

I agree; it's because of technical reasons that it makes no sense.

>> So it doesn't matter if you use udev, eudev, mdev or even a static
>> /dev directory; no init system wants to support a separate /usr
>> without an initramfs.
>
>
> Just fyi... the *only* problem that I have with this is that I have an
> *existing* system that has a separate /usr, and it only has that separate
> /usr because when I followed the original gentoo installation handbook back
> in 2003 or so, it actually had a separate /usr in the example directory
> structure layout, so I thought it was the official gentoo *recommendation*
> to do it that way.
>
> If I wasn't in this predicament, I'd just make a mental note to never
> install /usr to a separate partition and be done with it.
>
>
>> And for a good reason: is braindead.
>
>
> Again - it is only braindead if you accept the basic premise that it 'makes
> sense' to put files critical to the boot process into /usr.
>
> Personally, I think it only 'makes sense' to put files critical to the boot
> process into <gasp!> /boot.

What it's "critical" in the *general case*? It's NFS "critical"? It's
bluetooth "critical"? It's the network "critical"? It's LVM
"critical"? Are you going to put all of that in /boot or in /?

An initramfs covers all those cases (and many more). It doesn't matter
if some really simple cases could
possible-perhaps-if-the-stars-align-maybe work; the devs cannot
complicate the general case just to keep supporting some simple cases.
The devs want a *GENERAL* solution, that works for everybody.

That solution is an initramfs.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México

Re: [gentoo-user] where did lvm installation guide go?

[Tanstaafl]

On 2013-08-30 10:38 AM, Alan McKinnon <alan.mckinnon@gmail.com> wrote:
> On 30/08/2013 16:37, Tanstaafl wrote:
>> Personally, I think it only 'makes sense' to put files critical to the
>> boot process into <gasp!> /boot.

> It's not the boot process. It's the startup-to-early-init process.
>
> Or put another way, the entire start process up to the point where all
> of /usr is reliably available.
>
> "boot" is used here as very loose slang

Understood and point taken, but I think my point remains nevertheless...

Re: [gentoo-user] where did lvm installation guide go?

[gottlieb]

On Fri, Aug 30 2013, J. Roeleveld wrote:

> gottlieb@nyu.edu wrote:
>>I want to reinstall an old system to have combined root+usr.
>>
>>I have always used an lvm installation guide that was a "companion" to
>>the handbook.  That is it would tell you how to augment each handbook
>>installation chapter for lvm (actually lvm2).
>>
>>I can't find this documentation now on gentoo.org.  There is a big wiki
>>page, but that is different as are daniel's 2-volume "learning linux
>>lvm".
>>
>>The closest I found is the raid+lvm quick install guide, but i would be
>>happier with the one I have used often in the past.
>>
>>Any clues (I am emotionally prepared to learn that it is right there on
>>the installation web page, but my eyes and search commands are
>>deficient).
>>
>>thanks,
>>allan
>
> Allan,
>
> Use the raid+LVM guide and skip all the raid steps.
>
> --
> Joost

Yes, that is what I will be doing; but it is not the same as the "companion"
and hence less familiar to me.  Also the wiki certainly does help.
I haven't studied the raid+LVM closely yet but a quick look didn't
reveal how to interrupt the installation, shut off the machine, and
continue later.

Nonetheless, it is doubtless all there; just a loss of familiarity.

thanks,
allan

Re: [gentoo-user] where did lvm installation guide go?

[joost]

[-- Attachment #1: Type: text/plain, Size: 1642 bytes --]

gottlieb@nyu.edu wrote:
>On Fri, Aug 30 2013, J. Roeleveld wrote:
>
>> gottlieb@nyu.edu wrote:
>>>I want to reinstall an old system to have combined root+usr.
>>>
>>>I have always used an lvm installation guide that was a "companion"
>to
>>>the handbook.  That is it would tell you how to augment each handbook
>>>installation chapter for lvm (actually lvm2).
>>>
>>>I can't find this documentation now on gentoo.org.  There is a big
>wiki
>>>page, but that is different as are daniel's 2-volume "learning linux
>>>lvm".
>>>
>>>The closest I found is the raid+lvm quick install guide, but i would
>be
>>>happier with the one I have used often in the past.
>>>
>>>Any clues (I am emotionally prepared to learn that it is right there
>on
>>>the installation web page, but my eyes and search commands are
>>>deficient).
>>>
>>>thanks,
>>>allan
>>
>> Allan,
>>
>> Use the raid+LVM guide and skip all the raid steps.
>>
>> --
>> Joost
>
>Yes, that is what I will be doing; but it is not the same as the
>"companion"
>and hence less familiar to me.  Also the wiki certainly does help.
>I haven't studied the raid+LVM closely yet but a quick look didn't
>reveal how to interrupt the installation, shut off the machine, and
>continue later.
>
>Nonetheless, it is doubtless all there; just a loss of familiarity.
>
>thanks,
>allan

To continue, see my other email.
# vgchange -ay
That command will enable all the LVs it can find.
It works for me on all recent (last 2 years at least) installs with the sysrescuecd.

--
Joost
-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

[-- Attachment #2: Type: text/html, Size: 2280 bytes --]

Re: [gentoo-user] where did lvm installation guide go?

[Alan McKinnon]

On 30/08/2013 17:18, gottlieb@nyu.edu wrote:
> On Fri, Aug 30 2013, J. Roeleveld wrote:
> 
>> gottlieb@nyu.edu wrote:
>>> I want to reinstall an old system to have combined root+usr.
>>>
>>> I have always used an lvm installation guide that was a "companion" to
>>> the handbook.  That is it would tell you how to augment each handbook
>>> installation chapter for lvm (actually lvm2).
>>>
>>> I can't find this documentation now on gentoo.org.  There is a big wiki
>>> page, but that is different as are daniel's 2-volume "learning linux
>>> lvm".
>>>
>>> The closest I found is the raid+lvm quick install guide, but i would be
>>> happier with the one I have used often in the past.
>>>
>>> Any clues (I am emotionally prepared to learn that it is right there on
>>> the installation web page, but my eyes and search commands are
>>> deficient).
>>>
>>> thanks,
>>> allan
>>
>> Allan,
>>
>> Use the raid+LVM guide and skip all the raid steps.
>>
>> --
>> Joost
> 
> Yes, that is what I will be doing; but it is not the same as the "companion"
> and hence less familiar to me.  Also the wiki certainly does help.
> I haven't studied the raid+LVM closely yet but a quick look didn't
> reveal how to interrupt the installation, shut off the machine, and
> continue later.

the only difference is activating your LVs just before you need to mount
them (before doing the chroot):

vgchange -a y

everything else stays the same. Instead of mounting /dev/sdxy at
/mnt/gentoo/..., you will mount /dev/mapper/${LV}


> 
> Nonetheless, it is doubtless all there; just a loss of familiarity.
> 
> thanks,
> allan
> 


-- 
Alan McKinnon
alan.mckinnon@gmail.com

[gentoo-user] Re: where did lvm installation guide go?

[Nicolas Sebrecht]

On Fri, Aug 30, 2013 at 10:37:19AM -0400, Tanstaafl wrote:

> Just fyi... the *only* problem that I have with this is that I have an 
> *existing* system that has a separate /usr, and it only has that 
> separate /usr because when I followed the original gentoo installation 
> handbook back in 2003 or so, it actually had a separate /usr in the 
> example directory structure layout, so I thought it was the official 
> gentoo *recommendation* to do it that way.

Following the Gentoo original handbook at that time was the good thing
to do. But things change over time. What was true in 2003 might not
still be true today or tomorrow.

Things did change to the point that nowadays using an initramfs to keep
a seperate /usr filesystem is the way to go.

It's surprising you to have taken the handbook from Gentoo as best
practice guide to get a proper system and not beeing fine with the
recommendations of today.

> If I wasn't in this predicament, I'd just make a mental note to never 
> install /usr to a separate partition and be done with it.

Honestly, I used to have create a dedicated /usr filesystem for a long
long time. It really was a big plus in the past. Except of some corner
cases, I don't think it worth the trouble anymore.

-- 
Nicolas Sebrecht

Re: [gentoo-user] where did lvm installation guide go?

[gottlieb]

On Fri, Aug 30 2013, Alan McKinnon wrote:

> On 30/08/2013 17:18, gottlieb@nyu.edu wrote:
>> On Fri, Aug 30 2013, J. Roeleveld wrote:
>> 
>>> gottlieb@nyu.edu wrote:
>>>> I want to reinstall an old system to have combined root+usr.
>>>>
>>>> I have always used an lvm installation guide that was a "companion" to
>>>> the handbook.  That is it would tell you how to augment each handbook
>>>> installation chapter for lvm (actually lvm2).
>>>>
>>>> I can't find this documentation now on gentoo.org.  There is a big wiki
>>>> page, but that is different as are daniel's 2-volume "learning linux
>>>> lvm".
>>>>
>>>> thanks,
>>>> allan
>>>
>>> Allan,
>>>
>>> Use the raid+LVM guide and skip all the raid steps.
>>>
>>> --
>>> Joost
>> 
>> Yes, that is what I will be doing; but it is not the same as the "companion"
>> and hence less familiar to me.  Also the wiki certainly does help.
>> I haven't studied the raid+LVM closely yet but a quick look didn't
>> reveal how to interrupt the installation, shut off the machine, and
>> continue later.
>
> the only difference is activating your LVs just before you need to mount
> them (before doing the chroot):
>
> vgchange -a y
>
> everything else stays the same. Instead of mounting /dev/sdxy at
> /mnt/gentoo/..., you will mount /dev/mapper/${LV}

Thank you alan and joost.
I actually remembered -a y or -a -y and a search of the lvm commands
yielded vgchange.  But your replies definitely increased my confidence

allan