Addin physical volumes to a distributed volume group in a serviceguard cluster

[Andrew Kaplan]

Hi there --

I need to increase the size of a distributed volume group so that I can also resize several logical volumes within it. The volume group is within a serviceguard cluster.

I have already run the pvcreate command on the virtual disks, and I now I need to add them to the volume group in question. My next step is to undistribute the volume group, and I am ready to do so within SAM. My questions are the following:

1. Do I need to halt the serviceguard package the volume group is a member of, or the entire serviceguard service, prior to undistribution or is that not necessary?

2. If the answer to question one is no, will undistributing the volume group make it unavailable for general use?

3. After the physical volumes are added, and the logical volumes within the target volume group are extended, how do I redistribute the volume group?

4. Is the above the correct procedure to use, or is there something that I am missing or should be doing instead?

Thanks.

[Ivan Krastev]

Hello Andrew,

What you mean with distributed VG ?
If you VG is activated in normal cluster behavior (exclusive cluster mode, not the shared as it on RAC clusters)then the task is very simple:
1. Add physical volumes to VG on the node, where the goup is acivated.
2. Export VG map file (with -p option)!!!.
3. Copy map file to other node(s).
4. Run ioscan to check new disk availability on each node(s).
5. Export VG without preview on inactive node.
6. Create new VG info - directory, group file, so on .
7. vgimport VG from map file, from the source node.

If you have PVG distributed policy for LV's don't forget to keep copy of /etc/lvmpvg file and after importing VG add new + old disk entries for that group.

Regards,
ivan

[Andrew Kaplan]

Hi there --

Thanks for your reply. At the risk of sounding like a complete idiot. What would the command syntax be for steps 2,3,5,6, and 7?

Thanks.

[Ivan Krastev]

Commands:
2.On node1:
# vgexport -p -s -m /tmp/vg_shared.map /dev/vg_shared

3.# scp /tmp/vg_shared.map node2:/tmp/

Going to node2:
5.
# ls /dev/vg_shared/group - note minor number (0x020000 for example)
# vgexport vg_shared

6.
# mkdir /dev/vg_shared
# mknod /dev/vg_shared/group c 64 0x020000 (same minor here)

7.
# vgimport -v -s -m /tmp/vg_shared.map /tmp/vg_shared


regards,
ivan