Changing Minor number of VG

[Shibin_2]

Hi,

Can we change the minor number of VG, without removing the VG ?

Scenario is, I have created a VG of 400GB size in a cluster environemnt. When try to import it on another node, the same minor number, which I used for this VG, is using by another VG in that node.

If possible to change the Minor number without removing, that would be greatful. Otherwise, I have to recreate the whole thing.

Thanks in advance

[Shrikant Lavhate]

Hi,

Yes you can do it bu renaming VG. Whole procedure goes this way:


1) Umount file systems
2) vgchange -a n ----to deactivate vg
3) vgexport -m

[Robert-Jan Goossens_1]

Hi,

I'm not sure I understand your question. Would you like to change the minor online, while the VG is active?Then the answer in NO, you will need to vgexport/vgimport the VG.

# vgchange -a n /dev/vgxx
# vgexport -m /tmp/vgxx.map /dev/vgxx
# rm /dev/vgxx/group
# mknod /dev/vgxx/group c 64 0x0z0000
change the z
# vgimport -m /tmp/vgxx.map /dev/vgxx
# vgchange -a y /dev/vgxx

Hope this helps,
Robert-Jan

[Shibin_2]

Hi Shri,

Thanks for the quick response.

What if, I don't want to change the name of the VG ? Because, we have some standards and to keep this standard.

The pain is, I don't want to recreate, as it has total 16disks with it's PV Links.

[Shibin_2]

Hi Robert,

I will try this option.

I just created the VG. There is no data in it. But, the FS to be in cluster, so I need to replicate the same to other node. For the replication, I need to export this VG from this node and import it to another. When the importing stage, I found, the same minor number is using by some other VG and those are not part of cluster. Only local usage.

Anyway, I will try this option and come back to you guys.

[Shrikant Lavhate]

Interesting!
You are asking to bypass main thing for which whole thing meant for.....

Anyways I never tried like this as you said. But it should work I guess.

-=ShRi=-

[Shibin_2]

One more question, if I use the command

#rm /dev/vgxx/group

as said by Robert, will it remove the Minor number ??

Then, the Robert's option would be successful.

[Shrikant Lavhate]

yes.
Infact if you see same method is explained in both replies !!!

[Shibin_2]

Sorry to ask one more question.

Can I change the Max LV parameter, if the VG is not active ?

[Shibin_2]

Sorry to ask one more question.

Can I change the Max PV parameter, if the VG is not active ?