This post will cover how to correctly break a Netscaler HA pair, which might at first seem straightforward but just clicking that remove button will cause you all sorts of stress and more importantly downtime. Obviously because the Netscalers are in an HA pair means you want them and whats behind it to be highly available so any unavoidable downtime will be highly undesirable.
The process for correctly breaking an HA pair is as follows.
Logon to the web UI of both the primary and secondary node, and first make sure you know which is which as you certainly do not want to get any of this proceedure mixed up. Hit save on the primary node to ensure your running config is the same as the saved config.
On the Primary netscaler click on the System\High Availability configuration node and right click and open the secondary node.
Check the Stay Secondary radio box and hit OK, this will ensure that the secondary netscaler will not take any part of this process as a failure of the primary. This otherwise might lead to IP conflicts as both netscalers will be advertising the same IP address causing service outages.
So now both your netscalers should be showing this HA configuration.
Now right click the secondary node and select remove, once confirming that you have selected the correct node, click yes to remove the node and also yes again to propagate the change to the secondary node.
Once that has completed switch to the web ui of the secondary node and check the System/High Availability configuration node which should now look like this.
The netscaler HA pair has now been turned into two standalone netscalers with the same config on both. Changing the state on the secondary node would cause the same IP conflicts so we want to remove the config of the secondary and only leave the NSIP (netscaler IP) for management purposes. The easiest way to do this is goto the Diagnostics node and select the clear configuration option.
Then click the drop down list at the top of the screen and choose FULL, as described this will remove all the config except the NSIP so you will still be able to manage it and set it up for another purpose.
Hit Run when you are ready and wait for the process to complete.
When the config is clear it would now be a good idea to save the current config by hitting the save button at the top of web ui on both the old primary and secondary netscalers.
Author: Dale Scriven