[linux-lvm] lost volume group

[Petes Junk <crap central gmail com>]

When i was extending a group to include another PV somehow the Group
disappeared from the devices list after a reboot. 

The last entry in /dev/lvm/backup shows me executing
/usr/sbin/vgextend swampvg /dev/hdb2
to an already working /dev/swampvg/swamplv with a non striped /dev/hdb4
in it.

I then did a mkfs -t ext3 /dev/hdb2 (the new disk) which was probably
how i got into trouble. I really need the image from /dev/hdb4 and im
afraid to do anything with it without knowing exactly what im doing. Im
thinking all i need is to recreate the VG and LV with only /dev/hdb4. I
have several archives in the /dev/lvm/archive but docs are not clear how
to approach this. I backed up the partition to another with dd so i
could try work on it safely, but the LVM tools didnt like the fact that
it had two uuid labels the same and always picked /dev/hdb4 to work on.

Since then Ive been reading what little there is on LVM. Cant even find
a sysadmin book with more than 3 pages on the subject. Im very surprised
at the man page for vgcfgrestore where its options are not even
explained.

Any help is greatly appreciated. 

Pete