Need to vgimport of vg from cluster node

[Dhruva Raj]

Hi All,

I have a Cluster Env of 2 nodes.
I took a Flash Copy backup of the disk to another disk at SAN level of the Server_A (Cluster node). The backup disk is presented to another Server_C.
Now on Server_C i am trying to vgimport and then mount the fs. But when i run 'vgchange -a y vg_name' i get following error:
vgchange: Activation mode requested for the volume group "/dev/vgCMRdata" conflicts with configured mode.

1. Server_C is not a cluster node.
2. I have copied the map file from the Server_A (cluster node) to Server_C.
3. I have tried running 'vgchange -c n vgCMRdata'. cmds runs fine but this doesn't help.

Now, My question is:
Can we import the vg of a cluster node onto a non-cluster node? if yes, then what is that i need to do.

Please help me with your inputs.

Thanks & Regards,
Druva Raj

[S.N.S · Accepted solution]

Hi,

The answer would be -
In the shared VG of your Cluster, the activation need to be exclusively done - so that the multiple nodes of the cluster don't have access to the same Files and corrupt the instances like Oracle.(There is one exception to this tough, I don't remember - was is SGeRAC?) - this is theory

So practically, you should activate the VG exclusively by
vgchange -a e vg_name
This is the "configured mode"of SG
It should work just fine..

Then you would be able to import to a non-cluster node,

Any issues, let us know...

Aslo, pls be kind enough to assign points to All those who try to be of reasonable help .. :-)...

Thank you,

HTH
SNS

[Steven E. Protter]

Shalom,

You ask:
Now, My question is:
Can we import the vg of a cluster node onto a non-cluster node? if yes, then what is that i need to do.

Answer: Not when those disks are part of an activated volume group on node a or node b. A disk can not be activated at the same time in two different nodes unless it is activated in shared mode. To activate in shared mode all hosts would need to be part of the cluster, a criteria which is not met.

If you deactivate the volume group including the disks on both nodes of the cluster, then you might be able to activate the volume group on node c.

If you think about it, the reason is basic data protection. If a disk could be activated in two systems at the same time, havoc could occur on the data.

sEP

[Dhruva Raj]

Thanks for the replies.

SNS i have allocated the points..

However, i am still facing the problem. This is the process that i follow.

1. On Server_A, halt the corresponding pkg and run 'vgchange -a n vg_name' and 'vgchange -c n vg_name'
2. create the map file using following command:
vgexport -v -p -s -m /vgdata.map vgdata
3. Copy this map file to Server_C and import the vg using:
mkdir /dev/vgdata
mknod /dev/vgdata/group c 64 0x2a0000
vgimport -v -N -s -m /vgdata.map vgCMRdata
4. Now if i run 'vgchange -a y vgCMRdata'. O/P:
vgchange: Activation mode requested for the volume group "/dev/vgCMRdata" conflicts with configured mode.
5. If i run 'vgchange -a e vgCMRdata'
again i get same O/P:
vgchange: Cluster Services not available or unreachable on this system, for volume group "/dev/vgCMRdata".


Please help.

Thanks & Regards,
Druva Raj

[Steven E. Protter]

Shalom again,

I'm trying to help, but fear you are missing a basic concept.

Try this only if you can afford some downtime:

# Package must be DOWN.

Active node:
vgchange -a n vgCMRdata

Try it on the passive node as well, it won't hurt.

Now try the import.

You CAN NOT import a volume group containing a bunch of disks on a new system while these disks are active in a volume group on any other system.

If the OS let you do that there would be a lot of data corruption.

Question: Is this an Oracle RAC cluster? What mode is the shared volume group activated in?

SEP

[Benoy Daniel]

Try to do a vgchange -c n
then run again vgchange -c y

it should work.

[S.N.S]

Hi,

Need some clarifications:

Notice that you are exporting the VG named "vgdata"
but trying to export the VG named"vgCMRdata" ?!


At another angle:

1. For exclusive activation - the cluster daemon cmcld must be running on the node you are activating (the pkg can be down, though)

2. However, as I see now - I should have seen earlier, sorry - you can activate the vgCMRdata outside the cluster
Follow Melvyn:
http://forums13.itrc.hp.com/service/forums/questionanswer.do?admit=109447627+1271768825533+28353475&threadId=939886


Let us know your progress!


HTH
SNS

NB: Kindly excuse me for any confusion.

[Dhruva Raj]

After importing the vg, i was able to activate the vg in read mode.
How ever i could mount the filesystem in read only mode.