[linux-lvm] Re: What if a drive dies ?

[Måns Rullgård]

"Perplexer" <perplexer at thz.net> writes:

> Ahh I made a major typo .... it's a linear setup, not a striped one.
>
> You mentioned anyway that a recovery would be somewhat possible.
> I'm using ext3 journaling fs on my LV.

That's what I had.

> Would I be able to mount this LV if one PV died, meaning I would see
> all data except the part that was lost with that drive or would I
> need to do anything special to make the LV mountable again ?

It will depend on which part of the filesystem is lost.  I had a 10 GB
LV with various source code packages on it and lost maybe 2 GB
somewhere in the middle of it.  Obviously, everything on the dead disk
was lost.  The rest was mostly recovered, but many of the files ended
up in lost+found.

A different 20 GB LV had some 10-15 files each 0.5-1 GB in the root,
and no subdirectories.  This LV lost a GB or two at the beginning.
All the files were gone, even those that were stored entirely on a
good disk.  The reason for this was that all the inode information for
the root directory was stored on the bad part.

I don't know how other filesystems will deal with such situations.
I'm running RAID now to be somewhat safer.  It was a good thing too,
since one of the replacement disks turned out to be bad.

-- 
Måns Rullgård
mru at kth.se