Cannot export volume group without entry in /etc/lvmtab

[Damien Lass]

Hello all,
I am attempting to destroy a volume group using vgexport. The volume group does not have an entry in /etc/lvmtab. When I attempt to vgexport the volume group I receive the following error:
vgexport: Volume group "/dev/vgNN" does not exist in the "/etc/lvmtab" file.
vgexport: Couldn't export volume group "/dev/vgNN".

I need to export this volume group before I can re-import a new mapfile (with additional LVs) in its place. It Does anyone have any suggestions on how to get past this?

I have read a couple notes about re-building the /etc/lvmtab with a vgscan -v. Would this add back the volume group entry that is missing?

Any help would be greatly appreciated. Thanks in advance!

[A. Clay Stephenson]

Yes, first mv /etc/lvmtab /etc/lvmtab.sav and then do a vgscan.

[George Petrides_1]

Vgexport removes the volume group entry from the /etc/lvmtab file and deletes the /dev/vgXX directory. If you need to use the vgexport command to create the mapfile, then maybe you are better off creating it manually. I think the format is
1 lvol1
2 lvol2

George

[Fragon]

1. Using vgscan -v to rebuild your /etc/lvmtab file;
2. How about using "vgreduce and vgremove" to achieve your task?

-Gerald-

[Damien Lass]

All,
I ran a 'vgscan -a -v' and created a new /etc/lvmtab. This didn't fix my problem. The volume group (and associated disks) I want to replace does not show up in the /etc/lvmtab. Is there any way I can manually remove my /dev/vgNN from /dev with the following steps:
1) # cd /dev/vgNN
2) # rm -R * (to remove the 'group')
3) # cd ../
4) # rmdir vgNN
5) # vgimport -m vgNN.mapfile -v /dev/vgNN /dev/dsk/ctd
(where vgNN.mapfile is the mapfile I want to move in)

Is this a valid option to export a volume group? If so, is there anything else I need to do or watch out for?

Any other suggestions are welcome!

Thanks!

[Damien Lass]

To add to the message above... After reviewing my potential steps, I realized I am missing a couple steps. To add:

4)
5) mkdir /dev/vgNN
6) mknod /dev/vgNN/group c 64 0xNN00
THEN
7) vgimport -m vgNN.mapfile -v /dev/vgNN /dev/dsk/ctd

Sorry for the confusion!

[A. Clay Stephenson · Accepted solution]

When you make the group node for this vg, make absolute certain then the minor device number is unique. Look at the value in all the /dev/vgXX/groups and make sure that there is no conflict or absolute chaos will will.

e.g. mknod /dev/vg05/group c 64 0x050000 - 0x050000 should not be used anywhere else. By convention, vg05 uses 0x050000, vg02 uses 0x020000, etc. but that is not required (or may not be possible if already in use).

[Damien Lass]

I ended up following the steps outline in my message(s) above. It worked out fine. A reference to the volume group was added back to the original /etc/lvmtab once I re-imported and activated the new volume group.

Thanks everyone for your input.