[linux-lvm] pvmove root filesystem?

[Andreas Dilger]

On Nov 01, 2001  23:31 -0500, Brian J. Murrell wrote:
> Once I have copied the /boot from the ide disk to the scsi disk,
> and pvmoved the root filesystem (and possibly all of the rest of the
> filesystems in the rootvol) to the SCSI disk, I should be able to do
> the required "lilo" magic to get the MBR on the SCSI disk active and
> then make it the boot drive and reboot no?
> 
> Is there anything about pvmoving the root filesystem that I am missing
> in my description above that is going to cause disaster?

Brian, the "pvmove" mechanism is not yet 100% safe for mounted filesystems.
If there is little/no activity on the filesystem while it is being moved,
you are probably OK.  There may be a problem with the ext3 journal, it is
hard to say (there was a report on the ext3 mailing list, but I never got
enough details to sort it out.

What I would suggest (for the good of all people reading) is you do this:
1) Make a backup of everything (obviously).
2) Give it a try.
3) Tell us how it worked.  Ensure you run a full (forced) e2fsck on
   everything, preferrably after a reboot (I think if you create the
   file /forcedfsck or so, check your rc.sysinit or equivalent) it
   will do this at boot time.

It is critical that you have a full backup, as I say people have had
problems, and there are known "holes" in the pvmove locking.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/