[gentoo-user] remote installation, dual boot

[gentoo-user] remote installation, dual boot

[Stefan G. Weichinger]

I plan to install a fresh gentoo linux in parallel to an existing SLES
10 server.

The server runs with /boot and / on 2 raid1 devices, there is a large
RAID6 array building the PV for several logical volumes with data on it.

The idea is to have the server booted from live media (chroot does not
work as the current kernel of SLES is too old [1] ) ... install the new
gentoo-root into a new LV, set up dracut for an LVM-based root and place
the new kernel and initrd into the existing /boot (with old grub currently).

Should/could work, right?

The extra kick (again): the server is ~600 km away from me ;-)

I should keep up SLES as fallback as long as I got everything up and
running in gentoo. The server is doing backups to a tape library and
monitoring stuff via nagios ... the new feature to be enabled is KVM
virtualization (yes, the CPU is supporting this).

I have access via some "KVM over IP" so I can access the server console
directly in case (choice of boot option, repairing stuff).

Any particular tips for me?

The grub installed is grub-0.97-16.27.1 (SLES-release).
Is that expected to work with recent kernels/initrds? I assume.

I won't touch partitions/RAIDs/bootloader for now ... these things might
follow later when gentoo is working on the server.

Thanks, Stefan

[1] Linux version 2.6.16.60-0.66.1-smp

Re: [gentoo-user] remote installation, dual boot

[Mike Gilbert]

On Thu, Apr 23, 2015 at 10:49 AM, Stefan G. Weichinger <lists@xunil.at> wrote:
>
> I plan to install a fresh gentoo linux in parallel to an existing SLES
> 10 server.
>
> The server runs with /boot and / on 2 raid1 devices, there is a large
> RAID6 array building the PV for several logical volumes with data on it.
>
> The idea is to have the server booted from live media (chroot does not
> work as the current kernel of SLES is too old [1] ) ... install the new
> gentoo-root into a new LV, set up dracut for an LVM-based root and place
> the new kernel and initrd into the existing /boot (with old grub currently).

You should be able to get away with not using a livecd: you don't
really need to chroot to get an initial Gentoo system working,
*especially if you have console access*.

Some pointers:
- Unpack your stage tarball.
- Build the kernel and initramfs on an existing Gentoo system and copy
them over.
- Add the gentoo kernel and initramfs to menu.lst.
- Clear out the root password in /etc/shadow.
- Reboot the box.

You can then log in as root on the console, configure networking, and
run from there.

Re: [gentoo-user] remote installation, dual boot

[Stefan G. Weichinger]

On 23.04.2015 17:09, Mike Gilbert wrote:

> Some pointers:
> - Unpack your stage tarball.
> - Build the kernel and initramfs on an existing Gentoo system and copy
> them over.
> - Add the gentoo kernel and initramfs to menu.lst.
> - Clear out the root password in /etc/shadow.
> - Reboot the box.
> 
> You can then log in as root on the console, configure networking, and
> run from there.

hmm, yes, I see.
I have a gentoo server there so I have a "preparation machine" at hand.

I will see if I get that figured out ... got to get the kernel-options
and dracut modules right.

thanks, S

Re: [gentoo-user] remote installation, dual boot

[Stefan G. Weichinger]

On 23.04.2015 17:43, Stefan G. Weichinger wrote:

> I will see if I get that figured out ... got to get the kernel-options
> and dracut modules right.

first try started booting but couldn't mount rootfs ... and now the box
hangs there and I can't press the power button (only PS/2 attached
keyboard/mouse)

got to wait for the folks there to come to work tmrw ;-)

[gentoo-user] Re: remote installation, dual boot

[james]

Stefan G. Weichinger <lists <at> xunil.at> writes:

> 
> On 23.04.2015 17:43, Stefan G. Weichinger wrote:
> 
> > I will see if I get that figured out ... got to get the kernel-options
> > and dracut modules right.
> 
> first try started booting but couldn't mount rootfs ... and now the box
> hangs there and I can't press the power button (only PS/2 attached
> keyboard/mouse)
> 
> got to wait for the folks there to come to work tmrw 


There are methods to get the console terminal session, remotely.
One, is called "netconsole" [1]. I use to use this sort of thing
decades ago. How it is currently supported and the associated codes
(ssh) to use it remotely, I have not kept up with. Some headless embedded
system still use this sort of thing; with holes punched in the
routers/firewalls.....

I've also heard of folks setting up a serial console over serial-2-usb
converter, like ftdi, and then making a terminal session connection
form a remote cell phone to another cell phone, to tunnel an ascii
terminal session. I've never done this, but I'd be really curious how
somebody makes that sort of 9600 baud terminal connection to a remote
router or server, via a serial/console port.... using cell phones
as modems.

hth,
James



[1] https://www.kernel.org/doc/Documentation/networking/netconsole.txt

[2] http://www.mjmwired.net/kernel/Documentation/serial-console.txt 

Re: [gentoo-user] Re: remote installation, dual boot

[Stefan G. Weichinger]

On 23.04.2015 18:57, james wrote:
> Stefan G. Weichinger <lists <at> xunil.at> writes:
> 
>>
>> On 23.04.2015 17:43, Stefan G. Weichinger wrote:
>>
>>> I will see if I get that figured out ... got to get the kernel-options
>>> and dracut modules right.
>>
>> first try started booting but couldn't mount rootfs ... and now the box
>> hangs there and I can't press the power button (only PS/2 attached
>> keyboard/mouse)
>>
>> got to wait for the folks there to come to work tmrw 
> 
> 
> There are methods to get the console terminal session, remotely.
> One, is called "netconsole" [1]. I use to use this sort of thing
> decades ago. How it is currently supported and the associated codes
> (ssh) to use it remotely, I have not kept up with. Some headless embedded
> system still use this sort of thing; with holes punched in the
> routers/firewalls.....
> 
> I've also heard of folks setting up a serial console over serial-2-usb
> converter, like ftdi, and then making a terminal session connection
> form a remote cell phone to another cell phone, to tunnel an ascii
> terminal session. I've never done this, but I'd be really curious how
> somebody makes that sort of 9600 baud terminal connection to a remote
> router or server, via a serial/console port.... using cell phones
> as modems.

Thanks for the hint but for now I have to wait.

When I think about I have to add several kernel-options to menu.lst:

dracut has to assemble /dev/md3 at first (this is the single PV in the
VG VG01)

and /dev/VG01/genroot then is the filesystem with the new gentoo-rootfs

I only added stuff like rd.md=1 etc ... I think I got the assembling
wrong. And maybe even the root= option.

We will see tmrw if I get in early from other jobs.

Stefan

Re: [gentoo-user] Re: remote installation, dual boot

[J. Roeleveld]

On Thursday, April 23, 2015 07:21:12 PM Stefan G. Weichinger wrote:
> On 23.04.2015 18:57, james wrote:
> > Stefan G. Weichinger <lists <at> xunil.at> writes:
> >> On 23.04.2015 17:43, Stefan G. Weichinger wrote:
> >>> I will see if I get that figured out ... got to get the kernel-options
> >>> and dracut modules right.
> >> 
> >> first try started booting but couldn't mount rootfs ... and now the box
> >> hangs there and I can't press the power button (only PS/2 attached
> >> keyboard/mouse)
> >> 
> >> got to wait for the folks there to come to work tmrw
> > 
> > There are methods to get the console terminal session, remotely.
> > One, is called "netconsole" [1]. I use to use this sort of thing
> > decades ago. How it is currently supported and the associated codes
> > (ssh) to use it remotely, I have not kept up with. Some headless embedded
> > system still use this sort of thing; with holes punched in the
> > routers/firewalls.....
> > 
> > I've also heard of folks setting up a serial console over serial-2-usb
> > converter, like ftdi, and then making a terminal session connection
> > form a remote cell phone to another cell phone, to tunnel an ascii
> > terminal session. I've never done this, but I'd be really curious how
> > somebody makes that sort of 9600 baud terminal connection to a remote
> > router or server, via a serial/console port.... using cell phones
> > as modems.
> 
> Thanks for the hint but for now I have to wait.
> 
> When I think about I have to add several kernel-options to menu.lst:
> 
> dracut has to assemble /dev/md3 at first (this is the single PV in the
> VG VG01)
> 
> and /dev/VG01/genroot then is the filesystem with the new gentoo-rootfs
> 
> I only added stuff like rd.md=1 etc ... I think I got the assembling
> wrong. And maybe even the root= option.

This is one of the reasons why I have given up on genkernel and dracut for 
initramfs creation and now simply build my own and have it integrated into the 
kernel:
$ zcat /proc/config.gz | grep INITRAMFS_SOURCE
CONFIG_INITRAMFS_SOURCE="/usr/src/initramfs/config"

If you're interested I will send you the required files.

> We will see tmrw if I get in early from other jobs.

Good luck :)

--
Joost

[gentoo-user] Re: remote installation, dual boot

[james]

J. Roeleveld <joost <at> antarean.org> writes:


> This is one of the reasons why I have given up on genkernel and dracut for 
> initramfs creation and now simply build my own and have it integrated 
> into  the  kernel:
> $ zcat /proc/config.gz | grep INITRAMFS_SOURCE
> CONFIG_INITRAMFS_SOURCE="/usr/src/initramfs/config"

> If you're interested I will send you the required files.

> Joost


I'd be curious to look at exactly how you are doing this,
if you want to post them somewhere, or send me a copy too,
It would be appreciated.


James

Re: [gentoo-user] Re: remote installation, dual boot

[Stefan G. Weichinger]

On 24.04.2015 13:56, J. Roeleveld wrote:

>> dracut has to assemble /dev/md3 at first (this is the single PV in the
>> VG VG01)
>>
>> and /dev/VG01/genroot then is the filesystem with the new gentoo-rootfs
>>
>> I only added stuff like rd.md=1 etc ... I think I got the assembling
>> wrong. And maybe even the root= option.
> 
> This is one of the reasons why I have given up on genkernel and dracut for 
> initramfs creation and now simply build my own and have it integrated into the 
> kernel:
> $ zcat /proc/config.gz | grep INITRAMFS_SOURCE
> CONFIG_INITRAMFS_SOURCE="/usr/src/initramfs/config"
> 
> If you're interested I will send you the required files.

Yes, I am.

I looked at generating it via dracut and get confused a bit.

I try to generate it on another gentoo-host by editing a specific
dracut.conf whic contains the md-related lines:

kernel_cmdline+=" rd.md.uuid=6a6226ed:87d41201:76269125:1a17f6a4"
kernel_cmdline+=" rd.md.uuid=2d6cd278:5f966c0f:ac5ed5c3:5a0bb8f5"
kernel_cmdline+=" rd.md.uuid=b492f31d:96bfca88:8cd97590:ad997d2c"
kernel_cmdline+=" rd.md.uuid=e848b637:ca2bde73:9f92f3cc:128cdbad"

(to assemble the raid-arrays at boot)


I run

dracut -m "lvm mdraid bash" -c dracut.conf  -f init2.img 3.18.9-gentoo


and it ends with:

*** Store current command line parameters ***
Stored kernel commandline:
 rd.md.uuid=6a6226ed:87d41201:76269125:1a17f6a4
rd.md.uuid=2d6cd278:5f966c0f:ac5ed5c3:5a0bb8f5
rd.md.uuid=b492f31d:96bfca88:8cd97590:ad997d2c
rd.md.uuid=e848b637:ca2bde73:9f92f3cc:128cdbad
 root=UUID=6eafd21c-c5f4-496d-bb90-ab4dc0a2c93c
rootflags=rw,noatime,stripe=64,data=ordered rootfstype=ext4
*** Creating image file ***
*** Creating image file done ***


... so the root=  is looked up from the host I run the command on and
not fitting the target machine ... etc etc

hmm

Does root= inside the grub-config override these lines?

Should I use

dracut --no-hostonly-cmdline ?

Way too much variables in here ...  especially when I can't just press
Reset and try again.

Stefan

Re: [gentoo-user] Re: remote installation, dual boot

[Stefan G. Weichinger]

I now booted from a recent sysresccd ... and it didn't assemble/detect
the LVM-PV ... *sigh*

So I couldn't even mount the LV to chroot in there.

The mdadm-RAID-devices were there and active.

I didn't want to screw around with the LVM too much as there is data on
there (yes, there are backups, but ...).

pvscan always told me something like:

No device found for PV hMMm0m-w4Ds-SU77-ATjF-iF1A-0qfq-V2IcXb

 ....

When I boot into Suse again, it shows up fine:

# pvdisplay
  --- Physical volume ---
  PV Name               /dev/md3
  VG Name               VG01
  PV Size               4,09 TB / not usable 4,00 TB
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              1072103
  Free PE               242919
  Allocated PE          829184
  PV UUID               hMMm0m-w4Ds-SU77-ATjF-iF1A-0qfq-V2IcXb


Do I hit some compatibility-issue?

Stefan

Re: [gentoo-user] Re: remote installation, dual boot

[J. Roeleveld]

On 28 April 2015 10:33:32 CEST, "Stefan G. Weichinger" <lists@xunil.at> wrote:
>On 24.04.2015 13:56, J. Roeleveld wrote:
>
>>> dracut has to assemble /dev/md3 at first (this is the single PV in
>the
>>> VG VG01)
>>>
>>> and /dev/VG01/genroot then is the filesystem with the new
>gentoo-rootfs
>>>
>>> I only added stuff like rd.md=1 etc ... I think I got the assembling
>>> wrong. And maybe even the root= option.
>> 
>> This is one of the reasons why I have given up on genkernel and
>dracut for 
>> initramfs creation and now simply build my own and have it integrated
>into the 
>> kernel:
>> $ zcat /proc/config.gz | grep INITRAMFS_SOURCE
>> CONFIG_INITRAMFS_SOURCE="/usr/src/initramfs/config"
>> 
>> If you're interested I will send you the required files.
>
>Yes, I am.
>
>I looked at generating it via dracut and get confused a bit.
>
>I try to generate it on another gentoo-host by editing a specific
>dracut.conf whic contains the md-related lines:
>
>kernel_cmdline+=" rd.md.uuid=6a6226ed:87d41201:76269125:1a17f6a4"
>kernel_cmdline+=" rd.md.uuid=2d6cd278:5f966c0f:ac5ed5c3:5a0bb8f5"
>kernel_cmdline+=" rd.md.uuid=b492f31d:96bfca88:8cd97590:ad997d2c"
>kernel_cmdline+=" rd.md.uuid=e848b637:ca2bde73:9f92f3cc:128cdbad"
>
>(to assemble the raid-arrays at boot)
>
>
>I run
>
>dracut -m "lvm mdraid bash" -c dracut.conf  -f init2.img 3.18.9-gentoo
>
>
>and it ends with:
>
>*** Store current command line parameters ***
>Stored kernel commandline:
> rd.md.uuid=6a6226ed:87d41201:76269125:1a17f6a4
>rd.md.uuid=2d6cd278:5f966c0f:ac5ed5c3:5a0bb8f5
>rd.md.uuid=b492f31d:96bfca88:8cd97590:ad997d2c
>rd.md.uuid=e848b637:ca2bde73:9f92f3cc:128cdbad
> root=UUID=6eafd21c-c5f4-496d-bb90-ab4dc0a2c93c
>rootflags=rw,noatime,stripe=64,data=ordered rootfstype=ext4
>*** Creating image file ***
>*** Creating image file done ***
>
>
>... so the root=  is looked up from the host I run the command on and
>not fitting the target machine ... etc etc
>
>hmm
>
>Does root= inside the grub-config override these lines?
>
>Should I use
>
>dracut --no-hostonly-cmdline ?
>
>Way too much variables in here ...  especially when I can't just press
>Reset and try again.
>
>Stefan

I sent my files on a seperate thread last weekend.
Did you see those?

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

Re: [gentoo-user] Re: remote installation, dual boot

[Stefan G. Weichinger]

On 28.04.2015 17:30, J. Roeleveld wrote:

> I sent my files on a seperate thread last weekend.
> Did you see those?

no ... got to dig, thanks

Re: [gentoo-user] Re: remote installation, dual boot

[J. Roeleveld]

On 28 April 2015 17:37:06 CEST, "Stefan G. Weichinger" <lists@xunil.at> wrote:
>On 28.04.2015 17:30, J. Roeleveld wrote:
>
>> I sent my files on a seperate thread last weekend.
>> Did you see those?
>
>no ... got to dig, thanks

Sent on 25th. Initramfs in subject.

Happy hunting. :)
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Re: [gentoo-user] Re: remote installation, dual boot

[Stefan G. Weichinger]

On 28.04.2015 17:42, J. Roeleveld wrote:
> On 28 April 2015 17:37:06 CEST, "Stefan G. Weichinger" <lists@xunil.at> wrote:
>> On 28.04.2015 17:30, J. Roeleveld wrote:
>>
>>> I sent my files on a seperate thread last weekend.
>>> Did you see those?
>>
>> no ... got to dig, thanks
> 
> Sent on 25th. Initramfs in subject.
> 
> Happy hunting. :)

found, but too tired today to give that a try ...

thanks S

Re: [gentoo-user] Re: remote installation, dual boot

[J. Roeleveld]

On 28 April 2015 18:03:28 CEST, "Stefan G. Weichinger" <lists@xunil.at> wrote:
>On 28.04.2015 17:42, J. Roeleveld wrote:
>> On 28 April 2015 17:37:06 CEST, "Stefan G. Weichinger"
><lists@xunil.at> wrote:
>>> On 28.04.2015 17:30, J. Roeleveld wrote:
>>>
>>>> I sent my files on a seperate thread last weekend.
>>>> Did you see those?
>>>
>>> no ... got to dig, thanks
>> 
>> Sent on 25th. Initramfs in subject.
>> 
>> Happy hunting. :)
>
>found, but too tired today to give that a try ...
>
>thanks S

Oki.

Comments and questions about that please in the other thread.

With sufficient demand, I will collate the information and post it on the wiki.

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

Re: [gentoo-user] Re: remote installation, dual boot

[Stefan G. Weichinger]

On 28.04.2015 16:53, Stefan G. Weichinger wrote:
> 
> I now booted from a recent sysresccd ... and it didn't assemble/detect
> the LVM-PV ... *sigh*
> 
> So I couldn't even mount the LV to chroot in there.
> 
> The mdadm-RAID-devices were there and active.
> 
> I didn't want to screw around with the LVM too much as there is data on
> there (yes, there are backups, but ...).
> 
> pvscan always told me something like:
> 
> No device found for PV hMMm0m-w4Ds-SU77-ATjF-iF1A-0qfq-V2IcXb
> 
>  ....

ok, one step further:

(no exact cut and paste because of java-based KVM access)

pvscan --cache

tells me:

Found duplicate PV hMMm0m-w4Ds-SU77-ATjF-iF1A-0qfq-V2IcXb:

using /dev/sdj1 not /dev/md3

--

md3 is the correct array to form the PV ... /dev/sdj1 is actually a
partition that is an active *member* of the array /dev/md3

I tried to filter this partition by editing lvm.conf without success.

Under suse I don't see /dev/sdj1 as pv:

# pvdisplay /dev/sdj1
  Failed to read physical volume "/dev/sdj1"

-

Should I

* "pvremove /dev/sdj1" from sysresccd

* in suse: remove sdj1 from array md3 ... overwrite header and re-add ?

Oh my.

!! BUT ->

I now found another nice fact:

/dev/md2 (NO LVM) is unused since the initial installation.

I even *documented* that in the project wiki years ago.

40 GB of unused space on a RAID1 of SAS hdds. Nice!

Sounds like my new rootfs ;-)

dracut plus these md-lines should work then.

Stefan

Re: [gentoo-user] Re: remote installation, dual boot

[Stefan G. Weichinger]

On 28.04.2015 18:43, Stefan G. Weichinger wrote:

> 40 GB of unused space on a RAID1 of SAS hdds. Nice!
> 
> Sounds like my new rootfs ;-)
> 
> dracut plus these md-lines should work then.

call me "coward" or "defensive": I used genkernel ... and now the server
is up and running with gentoo linux ;-)

OK, way too much modules for now etc ... but booted.

btw: I learned about the kernel-option "panic=N" ... maybe this would
help in case the kernel does not detect the rootfs?

thanks all, Stefan