Adding one more node to a running MC service guard cluster

[praveenprashant]

Hi all,

I am new to MC service guard, I have a one scenario.

I have 2 node cluster running fine and i want to add one more node(third node) to this cluster.

I want to know the complete procedure to add this and what are precaution i should to take care before doing this.

Thanks

[VVS]

Below is the procedure:

1. Gather current cluster configuration as below:
cmgetconf â v â c temp.conf
2. Gather information about the new node as below:
cmquerycl â n node1 â n node2 â n new_node â C .conf.
3. Compare between these two files and update the cluster configuration file.
4. Verify the new configuration:
cmcheckconf â C .conf
5. Apply the new configuration:
cmapplyconf â C .conf
6. Start the new node:
cmrunnode

[praveenprashant]

Thanks for your quick response.

Please advice if any precautions i need to take care before implementing this.

Thx

[VVS]

Take the backup of cluster configuration file.

Thanks,
VVS

[Steven E. Protter]

Shalom,

Action here depends on your locking mechanism.

Last I checked, SG locking mechanism using a lock disk was only good for a two node cluster.

Therefore you might be advised to set up a quorum server to avoid contention and maintain stability.

I would have:
1) Ignite backups of both current nodes.
2) Back ups of all configuration files.
3) Warning tot he user community that work is being done and service interruption is not planned but possible.

SEP

[Foolqiu]

-1. Edir .rhosts & /etc/hosts and copy them to all nodes
0. Do the following at third node
# mkdir /dev/vgXX
# mknod /dev/vgXX/group C 64 0N0000
# vgimport -v -p (-s) -m map_file
1. Gather current cluster configuration as below:
cmgetconf -v -c temp.conf
2. Gather information about the new node as below:
cmquerycl -n node1 -n node2 -n new_node -C .conf.
3. Compare between these two files and update the cluster configuration file.
4. Verify the new configuration:
cmcheckconf -C .conf
5. Apply the new configuration:
cmapplyconf -C .conf
6. Start the new node:
cmrunnode