[linux-lvm] LVM help needed: conflicting names

[linux-lvm] LVM help needed: conflicting names

[Neil]

[Sorry about the dup; sent this to redhat-list earlier but just
 discovered this list which the more appropriate place.]

Hi-

I lost a machine (bad PS or MB -- disk is fine) and am trying to
bring up the disk in a second machine in order to access certain
filesystems from it.  The second machine's disk has a single
volume group 'vg0' containing several logical volumes, 'root',
'usr', 'home', etc (/boot is its own primary partition).
Unfortunately the disk from the dead machine is configured almost
identically, with a single 'vg0' volume group and some logical
partitions of the same name.

Booting with both disks in the machine fails; it gets totally
confused about which /dev/vg0/root (for example) it is supposed
to be using.  I think I can configure lvm.conf so that the second
disk is ignored by pvscan/vgscan during bootup, but I'm still
stuck on how to actually mount any of the second disk's LVM 
filesystems because of the name clashes.  Somehow I'd like to
rename the volume group on the second disk to 'vg1', for example.

Anybody have any ideas?

Thanks!
  Neil <nnc@newmexico.com>

Re: [linux-lvm] LVM help needed: conflicting names

[Dan B. Phung]

have you tried:

$ man vgrename

NAME
       vgrename - rename a volume group

DESCRIPTION
       vgrename renames an existing (see vgcreate(8) ) volume group

Examples
       "vgrename /dev/vg02 /dev/my_volume_group" renames existing volume 
group "vg02" to "my_volume_group".

       "vgrename vg02 my_volume_group" does the same.

-dan

On 5, Jun, 2005, Neil declared:

> [Sorry about the dup; sent this to redhat-list earlier but just
>  discovered this list which the more appropriate place.]
> 
> Hi-
> 
> I lost a machine (bad PS or MB -- disk is fine) and am trying to
> bring up the disk in a second machine in order to access certain
> filesystems from it.  The second machine's disk has a single
> volume group 'vg0' containing several logical volumes, 'root',
> 'usr', 'home', etc (/boot is its own primary partition).
> Unfortunately the disk from the dead machine is configured almost
> identically, with a single 'vg0' volume group and some logical
> partitions of the same name.
> 
> Booting with both disks in the machine fails; it gets totally
> confused about which /dev/vg0/root (for example) it is supposed
> to be using.  I think I can configure lvm.conf so that the second
> disk is ignored by pvscan/vgscan during bootup, but I'm still
> stuck on how to actually mount any of the second disk's LVM 
> filesystems because of the name clashes.  Somehow I'd like to
> rename the volume group on the second disk to 'vg1', for example.
> 
> Anybody have any ideas?
> 
> Thanks!
>   Neil <nnc@newmexico.com>
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 

-- 

Re: [linux-lvm] LVM help needed: conflicting names

[Neil]

On Sun, 2005-06-05 at 15:59 -0400, Dan B. Phung wrote:
> $ man vgrename

Crap (blushing); didn't know that command existed.  The
man pages for the other commands (e.g. vgchange) I was
investigating didn't mention that one.  Sorry!

Re: [linux-lvm] LVM help needed: conflicting names

[Alasdair G Kergon]

> > $ man vgrename
 
With two VGs with the same name, you may have to use a
temporary lvm.conf filter to "hide" one of them before 
renaming the other.

Alasdair
-- 
agk@redhat.com

Re: [linux-lvm] LVM help needed: conflicting names

[Neil]

On Sun, 2005-06-05 at 21:55 +0100, Alasdair G Kergon wrote:
> > > $ man vgrename
>  
> With two VGs with the same name, you may have to use a
> temporary lvm.conf filter to "hide" one of them before 
> renaming the other.

My problem turns out to be more insidious than I thought,
and I can't get even this far.  Both disks have the root
filesystem (not /boot) under LVM as /dev/vg0/root (fedora
core 3 systems), and it is initrd that is bailing when
it finds multiple /dev/vg0/root logical volumes.  The
lvm.conf file isn't even available at that stage.
Anybody know if there is a boot option to initrd that
filters which devices are examined for VG's?

-Neil

Re: [linux-lvm] LVM help needed: conflicting names

[Dan B. Phung]

sorry, but I can't remember your setup at the moment.  do you have two
disks booting on one machine?  what happens if you just boot one of the
disks to vgrename the logical volume, then shutdown and then hook the
other machine in.

On 5, Jun, 2005, Neil declared:

> On Sun, 2005-06-05 at 21:55 +0100, Alasdair G Kergon wrote:
> > > > $ man vgrename
> >  
> > With two VGs with the same name, you may have to use a
> > temporary lvm.conf filter to "hide" one of them before 
> > renaming the other.
> 
> My problem turns out to be more insidious than I thought,
> and I can't get even this far.  Both disks have the root
> filesystem (not /boot) under LVM as /dev/vg0/root (fedora
> core 3 systems), and it is initrd that is bailing when
> it finds multiple /dev/vg0/root logical volumes.  The
> lvm.conf file isn't even available at that stage.
> Anybody know if there is a boot option to initrd that
> filters which devices are examined for VG's?
> 
> -Neil
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 

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