Add-Remove Cluster node

Adding and removing cluster node

Adding a node into an existing cluster is a multi steps process.

1: Set up the hardware
Before adding a node to an existing cluster, node must be physically connected with the cluster.
1: Connect the VCS private Ethernet controllers
2: Connect the node to the shared storage

2: Install the VCS software in the node
Install the VCS software and install the license.

3: Configure LLT and GAB
Create the LLT & GAB configuration files (/etc/llthosts, /etc/llttab and /etc/gabtab) in the new node and update the files on the existing node.

4: Add the node to an existing cluster
We have to perform below given tasks in any of the existing node of a cluster
1: Make to cluster configuration R/W
# haconf –makerw

2: Add the new node to the cluster
# hasys –add <new node name>

3: Copy file from an existing node to new node
# scp /etc/VRTSvcs/conf/config/ new_node:/

4: Start vcs on the new node
# hastart

5: Now make the configuration again read only.
# haconf –dump –makero

5: Start VCS and verify the cluster
1: Start VCS on the new node
# hastart

2: Run the GAB configuration command on each node to verify that port a and port h include the new node in the membership.
# /sbin/gabconfig -a
Q-2 How to remove a node from an existing cluster?
Ans: Removing a node from a cluster includes many steps, which are given below:

1: Backup the configuration file
# cp /etc/VRTSvcs/conf/config/ /etc/VRTSvcs/conf/config/

2: Check the status of the nodes and the service groups
# hastatus –summary

3: Switch service group which is online on the node leaving the cluster
# hagrp –switch <service group> to <node name>

4: Delete the node from the VCS configuration
1: Make the cluster configuration R/W
# haconf –makerw

2: Stop the cluster on leaving node
# hastop –sys <node>

3: Delete the leaving node from the service group’s SystemList attribute.
# hagrp –modify <group> SystemList –delete <node>

4: Delete the node from the cluster
# hasys –delete <node>

5: Now again make the cluster configuration Read Only.
# haconf –dump –makero

5: Modify the LLT and GAB configuration files to reflect changes
Modify /etc/llthosts, /etc/llttab and /etc/gabtab files on the remining node on the cluster.

6: Remove VCS configuration on the node leaving the cluster
1: Unconfigure and unload LLT and GAB
# /sbin/gabconfig –U
# /sbin/lltconfig –U

2: Unload the LLT and GAB modules
# modunload –i <gab_module>
# modunload –I <llt_module>

3: Rename the startup files to prevent LLT, GAB and VCS from starting up in future.
# mv /etc/rc2.d/S70llt /etc/rc2.d/s70llt
# mv /etc/rc2.d/S92gab /etc/rc2.d/s92gab
# mv /etc/rc3.d/S99vcs /etc/rc3.d/s99vcs

4: Remove VCS package from the node