topic Re: Remove items in lvmtab in Operating System - HP-UX

Remove items in lvmtab

Kaleung Tsou — Wed, 30 Jul 2008 23:09:42 GMT

Hi,

I am trying to recreate a volume group called PBWbackup. The PBWbackup volume group was working fine until another administrator somehow removed it but the entries for it is still in lvmtab. thus, I am not able to recreate the VG PBWbackup. The lvmtab information is below.

PBWbackup has three disks associate with it. But the three disks are no longer presented to the system. I tried vgreduce, vgremove and it does not work. I tried renaming the lvmtab and did a vgscan. vgscan removed the PBWbackup entry, however, I have servicegard and I don't want to have to re-import all the VG that is associated with servicegard.

Please let me know if there is a way to just remove the PBWbackup VG.

Thanks

doux007:root 76> strings /etc/lvmtab
/dev/vg00
/dev/disk/disk7_p2
/dev/vg10
/dev/disk/disk190
/dev/vg01
/dev/disk/disk20
/dev/vg02
/dev/disk/disk23
/dev/vg03
/dev/disk/disk10
/dev/vg04
/dev/disk/disk13
/dev/vg_PRD0
/dev/disk/disk108
/dev/disk/disk111
/dev/vg_PRD1
/dev/disk/disk188
/dev/disk/disk189
/dev/disk/disk116
/dev/disk/disk191
/dev/disk/disk192
/dev/disk/disk193
/dev/vg_PRD2
/dev/disk/disk57
/dev/disk/disk60
/dev/disk/disk63
/dev/disk/disk66
/dev/disk/disk69
/dev/disk/disk72
/dev/vg_PBW0
/dev/disk/disk119
/dev/disk/disk122
/dev/vg_PBW1
/dev/disk/disk125
/dev/disk/disk128
/dev/disk/disk131
/dev/disk/disk134
/dev/disk/disk137
/dev/disk/disk140
/dev/vg_PBW2
/dev/disk/disk143
/dev/disk/disk146
/dev/disk/disk149
/dev/disk/disk152
/dev/disk/disk155
/dev/disk/disk158
/dev/vg05
/dev/disk/disk195
/dev/disk/disk208
/dev/vg06
/dev/disk/disk198
/dev/vg_PRD3
/dev/dsk/c11t4d7
/dev/dsk/c7t4d7
/dev/dsk/c5t4d7
/dev/dsk/c9t4d7
/dev/vg_nfs
/dev/dsk/c7t2d4
/dev/dsk/c5t2d4
/dev/dsk/c11t2d4
/dev/dsk/c9t2d4
/dev/dsk/c11t5d0
/dev/dsk/c7t5d0
/dev/dsk/c5t5d0
/dev/dsk/c9t5d0
/dev/PBWArchive
/dev/disk/disk221
/dev/PBWbackup
/dev/disk/disk225
/dev/disk/disk227
/dev/disk/disk232

Re: Remove items in lvmtab

skt_skt — Thu, 31 Jul 2008 00:51:04 GMT

"another administrator somehow removed it but the entries for it is still in lvmtab'

any idea how it was removed?

Re: Remove items in lvmtab

Patrick Wallek — Thu, 31 Jul 2008 01:20:59 GMT

If you are sure that the VG no longer exists, then you can try exporting the VG.

# vgexport /dev/PBWbackup

Re: Remove items in lvmtab

Deepak Kr — Thu, 31 Jul 2008 02:23:02 GMT

Yes, you don't need to re-export and import all the VGS again

vgexport is sufficient for removing the VG configuration when disks are not at all in use or in configuration itself.

Re: Remove items in lvmtab

Sujit — Thu, 31 Jul 2008 04:09:11 GMT

Run the command

#vgexport /dev/PBWbackup

If this VG is in cluster then same cmd. has to be run on other nodes. Be sure that this VG is not in use.

Re: Remove items in lvmtab

Torsten. — Thu, 31 Jul 2008 04:14:47 GMT

"another administrator somehow removed it but the entries for it is still in lvmtab'"

"somehow" is most of the times "rm" - the root cause of many serious problems ;-)

Next time you/he/she should use vgremove or vgexport. Otherwise you have a nice configuration mismatch like you currently have.

Re: Remove items in lvmtab

Kaleung Tsou — Thu, 31 Jul 2008 14:53:26 GMT

Thanks guys for the suggestion. The other someone is my supervisor and of course he is the type that never tells you what he did. He just tell you to fix it.

when I run vgexport /dev/PBWbackup I am getting the following error.

doux007:root 4> vgexport /dev/PBWbackup
vgexport: "/dev/PBWbackup/group": not a character device.
vgexport: Couldn't export volume group "/dev/PBWbackup"

Re: Remove items in lvmtab

Trevor Roddam_1 — Fri, 01 Aug 2008 06:17:40 GMT

Hi.

This situation normally arrises from just deleting the /dev/VGXX/* files.

You can't use vgexport because the files do not exist, only the entries in the lvmtab.
Therefore you can not create the VG of the same name as it already exists, according to the lvmtab.

Catch 22 (If anyone remembers to book/movie.

vgscan is the only way out.
To confirm this is the issue use
strings /etc/lvmtab

You should see the ghost VG entries stream past. If so, get you Mgr to read the link below on how to do it properly.

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad.pdf

The only way out is to use vgscan to recreate the lvmtab.
Look closely at the options, you can run it to see what would happen. Make sure what it comes up with is accurate and then do it for real. Have a BACKUP of the lvmtab before doing this. VERY Important.

I've used it in an emergency and, apart from the stress headache it worked a charm. But make sure it does the right thing before committing and rebooting.

Trevor.

Re: Remove items in lvmtab

Masud Parvez — Fri, 01 Aug 2008 07:53:08 GMT

Did you try to use this -

please do the following steps.....:
1. save /etc/lvmtab to another file
2. remove /etc/lvmtab
3. use vgscan(1m) -v to re-create /etc/lvmtab
4. NOW use vgcfgbackup(1m) to save the LVM setup

Re: Remove items in lvmtab

vjta — Wed, 06 Aug 2008 08:42:59 GMT

Hi!
as u r saying the vg is not there then simply run # vgexport

AS the vg is cluster awared make sure it is deactive or u can try #vgchange -c n

regards
vjta

Re: Remove items in lvmtab

vjta — Wed, 06 Aug 2008 08:44:33 GMT

Hi !
sorry pls read as
#vgchange -c n

regards
vjta

Re: Remove items in lvmtab

Kaleung Tsou — Wed, 06 Aug 2008 22:12:33 GMT

I exported all the vg that belongs to servicegard. Ran vgscan. Then import the exported vgs.