lvcreate on clustered vgs.

[Animesh Chakraborty]

hi all,
I think lvcreate can not be performed on "clustered VGs" i.e.
VGs which are under m/c service guard.
Any work around without halting the package ?
There is no data on those newly created Vgs.

Thanks in advance
Animesh

[Sridhar Bhaskarla]

Animesh,

You can create new logical volumes and make them part of MC/Service Guard while the package is running. You can create the logical volume with the normal procedure on the system where the volume group is activated. However, you need to update the package ascii file to include this new file system on both the system.

Next, you need to create the device files on the other node for this new logical volumes. Best thing would be to re-import the volume group on the other node with the new map files.

-Sri

[Animesh Chakraborty]

Hi Sridhar,
I have tried creating LVs using SAM but
it gives error :
lvcreate cannot be performed as the volume group is activated in shared mode.
I use all raw file systems so no need to recompile the ascii file.
Now If I do vgchange -c n /dev/vgxx then vgchange -a y /dev/vgxx then create LVs and back to vgchange -c y /dev/vgxx any effect to my pkg/cluster ? vgxx already there in cluster.

Thanks
Animesh

[Sridhar Bhaskarla]

Is there any reason why it's been activated as shared volume group?. Like are you running oracle parallel server?.

If not, you don't need to use the shared mode. The default mode supplied with the package template is good. If your volume group is activated in exclusive mode, then you can create new logical volumes in the Service Guarded volume groups. I don't use SAM to create logical volumes.

The process you mentioned should be ok.

Please let me know why you are using shared
mode for your volume group.

-Sri

[Animesh Chakraborty]

Hi,
My volume groups are in exclusive mode as they are part of a cluster. still getting that error mesg.Are the VGs under cluster treated as shared mode also ?not sure.
I am not usring any oracle paraller server.
we are using informix.

Thanks
Animesh

[Sridhar Bhaskarla]

Animesh,

It is very much possible if the volume group is activated only in exclusive mode.

I don't know why the volume group was activated in shared mode. Service Guard doesn't by default treat the volume groups in that way.

Try doing this.

On the other node do a vgchange -c y vgxx and vgchange -a n vgxx.
Now on the node where the volume group is activated, do a lvcreate manually.

#lvcreate -n lvxx -L 1000 vgxx
You don't need newfs as you are only using raw logical volumes.

If this is successful, then simply generate a map file here and import it on the other node.
Please let me know if this works.

If this doesn't work, when you get a chance, bring down the package and do a vgchange -c y and vgchange -a n on both the boxes and then bringup the pacakge.

-Sri

[Sanjay_6]

Hi,

As sridhar as already advised. This is how you do it.

If the vg is part of the cluster and is activated on a node say node 1, just create lv manually, export map and import map on the other node where the vg will be activated in the case of failover. You don't have to do a newfs as you say the filesystem is raw.

If on the other hand, the vg is part of the cluster but is not actiavted on any node, then activate on any node using "vgchange -a y /dev/vgxx" where the map for vgxx was impoted on this node earlier.
do lvcreate and export map, import on the other node, dectivate the vg from the previous node.

Once you have the vg in the ascii file during applying cluster conf, you wont have to make the vg cluster aware until you make it cluster unaware at any time.

Hope this helps

Thanks