[linux-lvm] Missing volume group

[Jay Sissom]

Hello, I made some changes to my LVM setup on my box and was surprised to
find that my volume group was gone when I turned on the computer this
afternoon.  I don't know if this is a bug or if I did something wrong.
I'll try to list all the things that I did.  I would appreciate if someone
could let me know if I did something wrong or if I uncovered a bug.  I
would also appreciate if someone could tell me how I could correct this
problem.

I have a RedHat 6.2 system with kernel 2.4.2.  I am using the lvm_mod
module directly from the 2.4.2 kernel.  I am using the lvm-0_9-1 rpm.

I have a volume group called storage made up of two partitions /dev/hda5
and /dev/hdb1.  Here is information about them:

[root at js /root]# pvdisplay /dev/hda5
--- Physical volume ---
PV Name               /dev/hda5
VG Name               storage
PV Size               20.49 GB / NOT usable 2.84 MB [LVM: 140 KB]
PV#                   1
PV Status             available
Allocatable           yes (but full)
Cur LV                1
PE Size (KByte)       4096
Total PE              5246
Free PE               0
Allocated PE          5246
PV UUID               dsQm1p-6sTR-Czku-d1eV-Wj6Y-R4al-QWVjA2

[root at js /root]# pvdisplay /dev/hdb1
--- Physical volume ---
PV Name               /dev/hdb1
VG Name               storage
PV Size               28.62 GB / NOT usable 3.7 MB [LVM: 149 KB]
PV#                   2
PV Status             available
Allocatable           yes (but full)
Cur LV                1
PE Size (KByte)       4096
Total PE              7327
Free PE               0
Allocated PE          7327
PV UUID               bsAfjN-20M6-tBcd-Zw1s-cb1B-SIO3-XktC1l

The physical volume /dev/hdb1 was 295 PE's smaller, so I extended it using
these commands:


umount /dev/storage/storage_lv

lvextend -l+295 /dev/storage/storage_lv

I then resized my ext2 file system:

resize2fs /dev/storage/storage_lv

mount /dev/storage/storage_lv /storage

This all worked great.  When I turned off my computer, then turned it on
later, the volume group was gone.

When vgscan was run, it gave this output:

[root at js /root]# vgscan
vgscan -- reading all physical volumes (this may take a while...)
vgscan -- no volume groups found

I searched and found out about the vgcfgrestore command and I ran these
commands:

[root at js /root]# vgcfgrestore -n storage /dev/hda5
vgcfgrestore -- VGDA for "storage" successfully restored to physical
volume "/dev/hda5"

[root at js /root]# vgcfgrestore -n storage /dev/hdb1
vgcfgrestore -- VGDA for "storage" successfully restored to physical
volume "/dev/hdb1"

[root at js /root]# vgchange -ay
vgchange -- volume group "storage" successfully activated

Now my volume is back, but I'm afraid it will disappear if I run vgscan
again.  I did the backup command to backup the configuration, but got
this:

root at js /root]# vgcfgbackup -v
vgcfgbackup -- finding all volume groups
vgcfgbackup -- volume group found: storage
vgcfgbackup -- locking logical volume manager
vgcfgbackup -- checking volume group name "storage"
vgcfgbackup -- checking existence of volume group "storage"
vgcfgbackup -- ERROR: volume group "storage" has an invalid number of
physical volumes
vgcfgbackup -- ERROR "vg_cfgbackup(): vg_check_exist" backing up volume
group "storage"

Any help fixing this would be greatly appreciated.  This volume has 45.5GB
of data on it and I don't have a tape drive that big!  I could restore it
if necessary, but really REALLY don't want to! :)

If this is a FAQ, please point me to the information.  I searched and
couldn't find anything.

Thanks
Jay