[lug] LVM and disk failure

[James Borley]

I have successfully removed a failing drive from an lvm2 volume group, 
and not lost any data, but I think I was very lucky. ;-)  However, I 
have a friend who lost a drive in his volume group and was able to 
recover everything except what was on the failed drive.  I don't recall 
the specifics, but I know it involved upgrading lvm1 to lvm2, then 
creating a place-holder for the failed drive so the filesystem would 
mount.  Check out the --partial option in the LVM man page.

Good luck!
-James

Daniel Webb wrote:
> I've been Googling for the answer to this and failing, so:
>
> What happens when you have a 2-disk LVM volume group and disk 1 fails?
> Obviously this will depend on the filesystem you put on top of the volume,
> right?  So which filesystems will recover gracefully if you chop them in half
> like that?
>
> It's a little disturbing that in all the documentation I've read on LVM this
> is never mentioned, and yet it seems to destroy the main purpose of lvm: to be
> able to add and remove disks to a volume easily.  Each physical volume you add
> makes it that much more likely that you'll lose the whole thing.  Sure, you
> can put it on top of RAID, but now you lost your size flexibility because RAID
> isn't so easy to resize (or is it?).  The snapshots feature is nice, that's
> all I'll use it for until I find a satisfactory answer to this question.
>
> I also was checking out evms and it looks very interesting.  Any impressions
> from those who have used it?  Is it stable/reliable?  I didn't see anything in
> their docs either about recovering when one disk in a volume fails.
>
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