Re: LVM - dead disk
On Apr 1, 2006, at 21:14, Klaus Pieper wrote:
Which file systems are (or maybe were) on lvm? Do you need lvm to
boot up the system? What about backups?
Klaus
I do have some backups (amanda to dds3 dat) - so - it's not going to
be a crisis if I can't get it fixed (although - getting the lastest
copy of stuff would be good)
But - I thought this would be a good chance at trying to learn more
about retrieving data when systems go bad. There is no large hurry to
getting the box back up - so I'm willing to hack at it a bit - try to
understand how to work with this kind of problem.
So - on to the system - /usr, /var, /home, /opt, /srv and /store were
on lvm
/store is the dead disk - so that's out of the picture.
/opt, /srv, /usr - no useful info - /opt and /srv are just play areas
- /usr is all reinstallable from the packages.
/etc is not on lvm - and is sitting there fine and pretty :)
So - I'm really after /home and /var/lib
All were backed up more or less often (there is a limit as to how
much data a DDS3 can take). But - not being a prioritised box - it
tends to be weekly rather than daily.
So - we've used the vgreduce command to remove the dead disk.
For some reason I can no longer log in. I may well have caused this
myself - but it may be linked to the fact that this machine has
nsswitch for login on ldap compat - and of course the ldap data is
on /var/lib - however - the compat should let me in (I see root in
the passwd and shadow files). And - it seems odd that it does not see
a hostname.
So - I thought I'd try to chroot in from a CD live disk - knoppix was
what I had lying around (4.0) - but that doesn't have lvm or has an
lvm version difference.
Some time next week - I'll be sticking three new 250Gb disks into it
and reinstalling from scratch - but - I'd like to attempt to get the
data off if at all possible. Each time something goes wrong you learn
a bit - you know ? :)
So - is there a live cd out there (or an install set or similar) that
will boot far enough to allow me to chroot in and then load the
virtual group? Or is there a better way?
In fact - I'm more after hints/tips on how to go about investigating/
troubleshooting this one than just getting the data back :)
And - with a bit of luck I'll manage to send this reply to the list
directly first time this time :)
Chris Searle
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