Changing the group id of a VxVM disk group

[huebs]

Does anybody know a way to change the group id of a veritas volume manager (4.0) disk group?

A group was copied using HDS Shadow Image to another bunch of disks and importet on the target system with a new name. The group ids remain identical ... which is fatal if a host sees both disk groups, and our backup server has to do

Some sources in the web say it can't be done, others mention vxprivutil. I can't find any detailed docs about this tool.

 

[Annihilannic]

Provided you can still import the disk group from one of the hosts, you can rename the disk group by deporting it and re-importing it with vxdg -n newname oldname.

Annihilannic.

 

[Annihilannic]

Duh. vxdg -n newname import oldname.

I notice you can also rename it on deport with v4.0.

Annihilannic.

 

[huebs]

That's what I did during the import procedure on the target host. The name changed, the problem is the ID, which remains the same.

 

[huebs]

To describe it in detail:

oldhost# vxdg list oldname-dg
Group:    oldname-dg
dgid:     1234567890.1234.oldhost
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...

newhost# vxdg list newname-dg
Group:    newname-dg
dgid:     1234567890.1234.oldhost
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...

The dgid is exactly the same in both groups and does not change on "import newname".

 

[huebs]

To work around the problem, I finally splitted the mirrors, created a new dg with half of the disks and copied the data using cpio.

If somebody knows a way to change this disk group id, please let me know!

Thanks,
Huebs
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[Annihilannic]

Sorry, I thought that changed the disk group ID as well.

Here's another option:

# save objects in disk group to file
vxprint -g diskgroup -vpsm > /tmp/dgfile
vxdisk -g diskgroup list > /tmp/disks

# destroy original disk group (data remains on disks)
vxdg destroy diskgroup

# re-create disk group (generates new dgid)
vxdg init diskgroup somediskname=cXtXdX

# re-add remaining disks (refer to /tmp/disks)
vxdg -g diskgroup adddisk anotherdiskname=cXtXdX

# re-create volume manager objects from saved file
vxmake -g diskgroup < /tmp/dgfile

# re-start volumes
vxvol -g diskgroup startall

I take no responsibility if it goes wrong!

Annihilannic.

 

[huebs]

Thanks Annihilannic,

I wrote a script like this to move volumes to another disk group (print,destroy,make) ... already tried it to change the group id without success.
I'll give it another try on a test system.

Huebs
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