| View previous topic :: View next topic |
| Author |
Message |
weird wonko
Tux's lil' helper
Joined: 05 Jan 2003
Posts: 141
|
 Posted: Wed Jan 12, 2005 12:25 am Post subject: LVM2: Couldn't find device with uuid... [solved] |
 |
|
I set up LVM2 some days ago, without problems. But today my box crashed, and after rebooting, I get "Couldn't find device with uuid" errors. With /usr, /var, /home, /opt and /tmp being on logical volumes, nothing is working now. I do not know what the error is, if it came by the crash, or if I did something. I found some postings here and in usenet, but nothing that really helped me. There are some things I will try, but I do not know much about LVM2 yet and I really do not want to lose my data, so I hesitated. Maybe someone here knows what's wrong, I hope so.
More detail. This is the setup I had:
| Code: | hda1 /boot 16M
hda2 swap 1.5G
hda3 / 1G
hda5 lvm0 20G
hda6 lvm0 20G
hda7 /data 75G
|
All was fine, rebooting was no problem. But my home partition was too small, so the plan was to delete the /data partition and create more LVM partitions (20 G each) for my lvm0 volume group, and to resize my /home then.
I first set up another volume group on an external USB drive to backup the /data partititon, this was no problem, and this volume group is still okay. Then I deleted hda7 and created hda7 to hda10. I used vgextend to add hda7 to the lvm0 volume group.
That's it, I did nothing more yet. One day later (without rebooting), X suddenly crashed (probably due to emerging a new xorg-x11), even the text mode was affected, I had to reboot. And from now on I no longer have the lvm0 group, because a device cannot be found.
lvdisplay gives this output:
| Code: | --- Physical volume ---
PV Name /dev/hda5
VG Name lvm0
PV Size 19.07 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 4882
Free PE 0
Allocated PE 4882
PV UUID pLrBnp-GFg5-Vo7r-7f6v-rgei-kFjD-7kYJKI
--- Physical volume ---
PV Name /dev/hda6
VG Name lvm0
PV Size 19.07 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 4882
Free PE 36
Allocated PE 4846
PV UUID ckjttL-JX0i-JDwv-qPXp-Nzhh-2VLp-1Av2qY
--- Physical volume ---
PV Name unknown device
VG Name lvm0
PV Size 68.46 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 17527
Free PE 17527
Allocated PE 0
PV UUID bKQmb3-BPL3-eZd0-qcpZ-1QoP-DHq3-2S6R6R
|
The last uid (bkQ...) is the one that cannot be found. It probably is on the hda7 partition I just added to the lvm0 volume group. Maybe I could just delete it, but I do not want to lose data. In fact, that's what I just did some days ago, I accidentally rm -rf'ed most of my system, and what I am working with now is the backup.
Sorry if this sounds confused, but I am confused, tired, and hjave no clue what is going on.
Meta question: Is LVM easy? Do I need to know it in detail? I have it running already for half a year on another PC, and had no problems yet. Wiping my disk accidentally gave me the chance to change my main system to LVM. LVM gives much more flexibility, but if something goes wrong, I am in deep trouble.
Thanks for reading,
Wonko
Last edited by weird wonko on Fri Jan 14, 2005 12:17 pm; edited 1 time in total |
|
| Back to top |
|
 |
nemo_
Apprentice
Joined: 19 Sep 2002
Posts: 167
Location: Brussels, Belgium
|
| Posted: Fri Jan 14, 2005 8:48 am Post subject: |
|
|
what does pvdisplay /dev/hda7 say ?
you might want to look at vgcfgrestore, assuming you have a config backup in /etc/lvm (which _should_ be the case).
here's an excerpt from vgcfgrestore's man page :
| Quote: | REPLACING PHYSICAL VOLUMES
vgdisplay --partial --verbose will show you the UUIDs and sizes of any PVs that are no longer present. If
a PV in the VG is lost and you wish to substitute another of the same size, use pvcreate --restorefile
filename --uuid uuid (plus additional arguments as appropriate) to initialise it with the same UUID as the
missing PV. Repeat for all other missing PVs in the VG. Then use vgcfgrestore --file filename to restore
the volume group's metadata. |
if your hda7 physical volume is ok I guess you can restore the LVM config by forcing the UUID as stated there but I've never had to do something like that so far .. |
|
| Back to top |
|
|
weird wonko
Tux's lil' helper
Joined: 05 Jan 2003
Posts: 141
|
| Posted: Fri Jan 14, 2005 12:15 pm Post subject: |
|
|
I just fixed the problem. No data was lost, all seems to be fine again. I feel better now 
I first backupped the partitions with dd to another drive (after moving around lots of data to create the 2x20 G free space), then I tried some things that were mentioned in other posts here and on usenet, like using vgcfgrestore, without success. (nemo_, I did this last night so I did not try the --partial option you mentioned. But thanks anyway, I think this solution should also have worked.)
I also deleted the additional hda7 to hda10 partitions I had created, so the layout was the same as before. This also didn't help.
Then I had a closer look at the /etc/lvm/backup directory. There is a lvm0 file containing information about this logical volume, with a list of physical volumes. pv0 (hda5) and pv1 (hda6) seemed to be okay, but there was also a pvm2 entry, with the uuid that gave me the trouble. This came from my pvcreate /dev/hda7 and vgextend lvm0 /dev/hda7 commands. Maybe I just forgot to issue vgchange -a n after that? I still don't know. But after commenting out this entry, all was working fine again.
Wonko |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
Kernel & Hardware
