[linux-lvm] moving single LVM disk from one system to another

[linux-lvm] moving single LVM disk from one system to another

[lvm]

My workstation died (the MB, not the disk).  :-(

In it I have a single ATA disk with three fdisk type partitions:

hd?1 Linux boot
hd?2 Windows ~hangs head in shame~ (it's for testing only :-)
hd?3 LVM

Inside the LVM partition is the root, swap and a couple of other
filesystems.  On the ext3 /boot partition there is an initrd with all
the magic in it to get LVM and ext3 up and running.

On the dead machine, where the disk was built and last running, the
disk was device /dev/hde on a Promise ATA100 bus.  I want to move it
to another (working) machine on the primary ATA bus so it will be
/dev/hda.

When I boot the system, the initrd fires up and runs a vgscan but it
does not find the rootvol volume group.  So I boot on my Linux
distro's boot CD in rescue mode, install the LVM module, run vgscan
(the vendor was nice enough to put the lvm tools on the boot/rescue
cd) and it finds it fine.  I run "vgchange -a y" and whammo, the
volume group is active and I can mount my rootfs.  Great.  So I chroot
the HD (LVM) rootfs and mount /boot and run vgscan again so that it
updates the /etc/lvm* stuff and also build a new initrd, hoping that
the new configuration information will make it into the initrd.

I reboot again and still vgscan finds no volume groups.  What am I
missing here?  Why can the rescue mode of the boot CD find the volume
group no problem with a vgscan and my initrd's vgscan cannot?

Thanx in advance for any enlightment.

b.

-- 
Brian J. Murrell

Re: [linux-lvm] moving single LVM disk from one system to another

[Goetz Bock]

On Sat, Aug 17 '02 at 03:09, lvm@interlinx.bc.ca wrote:
> My workstation died (the MB, not the disk).  :-(
> [ ... ]
> On the dead machine, where the disk was built and last running, the
> disk was device /dev/hde on a Promise ATA100 bus.  I want to move it
> to another (working) machine on the primary ATA bus so it will be
> /dev/hda.
Just a poke in the dark, but maybe your kernel get's the disks CHS
information wrong on bootup. But hopefully you can force this on the
mobo's BIOS.
-- 
Goetz Bock       (c) 2002 as     blacknet.de - Munich - Germany   /"\
IT Consultant    GNU FDL 1.1    secure mobile Linux everNETting   \ /
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 ASCII Ribbon Campaign against HTML email & microsoft attachments / \

Re: [linux-lvm] moving single LVM disk from one system to another

[lvm]

On Sat, Aug 17, 2002 at 12:50:58PM +0200, Goetz Bock wrote:
> 
> Just a poke in the dark, but maybe your kernel get's the disks CHS
> information wrong on bootup. But hopefully you can force this on the
> mobo's BIOS.

But then, wouldn't the bootable CDROM that I can boot from and use
vgscan to find the LVs have the same trouble?

b.

-- 
Brian J. Murrell

Re: [linux-lvm] moving single LVM disk from one system to another

[Heinz J . Mauelshagen]

Is that with our without devfs?
Have you checked, that device nodes are in your initrd for vgscan to be able
to access them fine?
Does vgscan fail finding your VG our is it just wrong entries in /etc/fstab
failing your root mount?

On Sat, Aug 17, 2002 at 03:09:02AM -0400, lvm@interlinx.bc.ca wrote:
> My workstation died (the MB, not the disk).  :-(
> 
> In it I have a single ATA disk with three fdisk type partitions:
> 
> hd?1 Linux boot
> hd?2 Windows ~hangs head in shame~ (it's for testing only :-)
> hd?3 LVM
> 
> Inside the LVM partition is the root, swap and a couple of other
> filesystems.  On the ext3 /boot partition there is an initrd with all
> the magic in it to get LVM and ext3 up and running.
> 
> On the dead machine, where the disk was built and last running, the
> disk was device /dev/hde on a Promise ATA100 bus.  I want to move it
> to another (working) machine on the primary ATA bus so it will be
> /dev/hda.
> 
> When I boot the system, the initrd fires up and runs a vgscan but it
> does not find the rootvol volume group.  So I boot on my Linux
> distro's boot CD in rescue mode, install the LVM module, run vgscan
> (the vendor was nice enough to put the lvm tools on the boot/rescue
> cd) and it finds it fine.  I run "vgchange -a y" and whammo, the
> volume group is active and I can mount my rootfs.  Great.  So I chroot
> the HD (LVM) rootfs and mount /boot and run vgscan again so that it
> updates the /etc/lvm* stuff and also build a new initrd, hoping that
> the new configuration information will make it into the initrd.
> 
> I reboot again and still vgscan finds no volume groups.  What am I
> missing here?  Why can the rescue mode of the boot CD find the volume
> group no problem with a vgscan and my initrd's vgscan cannot?
> 
> Thanx in advance for any enlightment.
> 
> b.
> 
> -- 
> Brian J. Murrell
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html

-- 

Regards,
Heinz    -- The LVM Guy --

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen@Sistina.com                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Re: [linux-lvm] moving single LVM disk from one system to another

[lvm]

On Mon, Aug 19, 2002 at 10:24:27AM +0200, Heinz J . Mauelshagen wrote:
> 
> Is that with our without devfs?

Interesting you should ask.  :-)

> Have you checked, that device nodes are in your initrd for vgscan to be able
> to access them fine?

I am/was (for the past hour or two) just hunting this possibility
down.  I have the system currently booting from a tftp server (via an
etherboot diskette) so that I can shorten the cycle of "modify initrd
with more debugging and re-test".  I am just about to put some
debugging into the native hard disk booting initrd to see what disk
nodes are there and such.

The kernel is being booted with "devfs=mount", so they should be
there.  I should know in a few more minutes what is going on.

> Does vgscan fail finding your VG our is it just wrong entries in /etc/fstab
> failing your root mount?

vgscan fails to find the VG.  I am sure this is going to turn out to
be missing device nodes, but will have figure out why that is if devfs
is being mounted.

Will keep ya posted.

b.

-- 
Brian J. Murrell

Re: [linux-lvm] moving single LVM disk from one system to another

[lvm]

OK.  To update:  it would seem that for whatever reason, devfs _is_
being mounted (cat /proc/mounts shows devfs on /dev and .devfsd is in
/dev) but there are no device nodes under
/dev/ide/host0/bus[01]/target0/.  Strange.  But that explains why
vgscan could not find the VG.

The ide devices are seen by the kernel.  /proc/ide/hd?/model shows the
disk and CD R/W devices.  /proc/partitions is empty however.  Very
strange.  I will have to dig in and figure out why this is.  All and
any theories are welcome.  :-)

But the long and short of my problem is that it's not an LVM problem.
Not directly anyway.

b.

-- 
Brian J. Murrell

Re: [linux-lvm] moving single LVM disk from one system to another

[lvm]

[-- Attachment #1: Type: text/plain, Size: 1222 bytes --]

It's embarassing but I will come clean...

On Mon, Aug 19, 2002 at 06:04:57AM -0400, lvm@interlinx.bc.ca wrote:
> 
> there are no device nodes under
> /dev/ide/host0/bus[01]/target0/.  Strange.

Not so strange once I looked more closely.  To try to soften the
embarassment, let me explain.  I am moving a disk from one motherboard
to another.  The board the disk was created on had two pairs (primary
and secondary times two) of IDE ports.  Regular, ol' IDE on ports
on hda-hdd and ATA100 on ports hde-hdh.

Since the disk in question is an ATA 100 disk, I put it on hde to take
advantage of the faster bus speed.  Not wanting to waste "good" ATA
100 ports on silly devices like CD-RW drives I put mine on hda.  And
of course since it's a writer, added "hda=ide-scsi" to the kernel
command line.  I think you know where this is going.

In moving the disk to the new motherboard, it only has a single pair
of IDE ports (primary and secondary), all ATA100, hda-hdd.  So,
naturally, I put the disk on hda, which was being masked by the
hda=ide-scsi kernel parameter.  Thus the empty /dev/ide/.../lun0/
directory.

Sorry to bother y'all with such a silly mistake.  :-)

b.

-- 
Brian J. Murrell

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Re: [linux-lvm] moving single LVM disk from one system to another

[Heinz J . Mauelshagen]

On Mon, Aug 19, 2002 at 08:24:00AM -0400, lvm@interlinx.bc.ca wrote:
> It's embarassing but I will come clean...
> 
> On Mon, Aug 19, 2002 at 06:04:57AM -0400, lvm@interlinx.bc.ca wrote:
> > 
> > there are no device nodes under
> > /dev/ide/host0/bus[01]/target0/.  Strange.
> 
> Not so strange once I looked more closely.  To try to soften the
> embarassment, let me explain.  I am moving a disk from one motherboard
> to another.  The board the disk was created on had two pairs (primary
> and secondary times two) of IDE ports.  Regular, ol' IDE on ports
> on hda-hdd and ATA100 on ports hde-hdh.
> 
> Since the disk in question is an ATA 100 disk, I put it on hde to take
> advantage of the faster bus speed.  Not wanting to waste "good" ATA
> 100 ports on silly devices like CD-RW drives I put mine on hda.  And
> of course since it's a writer, added "hda=ide-scsi" to the kernel
> command line.  I think you know where this is going.
> 
> In moving the disk to the new motherboard, it only has a single pair
> of IDE ports (primary and secondary), all ATA100, hda-hdd.  So,
> naturally, I put the disk on hda, which was being masked by the
> hda=ide-scsi kernel parameter.  Thus the empty /dev/ide/.../lun0/
> directory.
> 
> Sorry to bother y'all with such a silly mistake.  :-)

Well, the wonderful world of PC style peripherals :(

> 
> b.
> 
> -- 
> Brian J. Murrell



-- 

Regards,
Heinz    -- The LVM Guy --

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen@Sistina.com                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-