How to fix two disks with the same Volume Group?

[Da Rock]

On Thu, 2008-03-20 at 11:38 +0000, Luciano Rocha wrote:
> On Thu, Mar 20, 2008 at 08:58:04PM +1000, Da Rock wrote:
> > 
> > On Thu, 2008-03-20 at 10:22 +0000, Luciano Rocha wrote:
> > > You can use the install/recovery disc for Fedora. On the command line,
> > > you'll have to prefix the lvm commands with lvm, like this:
> > > 
> > > lvm pvscan
> > > lvm vgscan
> > > lvm vgchange
> > > ...
> > > 
> > 
> > Good to know- a shortcut. Is this under repair on the install cd?
> 
> Yes, or you can boot to the installation screen, then switch to the 2nd
> console (ctrl+alt+f2), where you'll find a command prompt.
> 
> > > 1. edit grub.conf, change root= to the new name
> > > 2. edit etc/fstab, change swap, root, etc. to use new name
> > > 3. re-create initrd, as it has the vg name hardcoded:
> > >    mkinitrd -f -v /boot/initrd-`uname -r`.img `uname -r`
> > > 
> > > You can do this while the system is running, and then reboot. No need
> > > for recovery/lice cd (if everything goes fine; you'll need it if the
> > > system no longer boots).
> > > 
> > 
> > Surely not if you've just changed the name using the repair disk? But
> > very succinctly put- I've only done this once and it took several hours
> > following from instructions on a page. I had trouble remembering the
> > exact steps myself.
> 
> Yes, if the change was made in the repair disk, the kernel version will
> probably be different, and the paths are relative to the system's root.
> 
> But the rename can be done while the system is running, so only the
> followin pass is missing:
> 0. vgrename ...
> 
> > > I'd suggest that new Fedora releases create a random name for the VG and
> > > that their initrd/nash support getting the vg from the root= kernel
> > > command line.
> > > 
> > > Regards,
> > > Luciano Rocha
> > 
> > You don't think setting it to the machine name is any good? Given
> > current install procedures, what do you suggest to prevent this?
> > Obviously something manually.
> 
> Currently the filesystem is defined before the network (and, thus, the
> hostname). Also, you might have two different installations with the
> same hostname (like a new install to a new set of hard disks).
> 
> But I do use the hostname as the VG, so I think that's best, probably
> with current date appended (like: hostname080320).
> 
> Regards,
> Luciano Rocha

Good to know. Thanks