I am managing a 2 node Red Hat cluster that hosts a bunch of virtual machines; recently, the combined memory use for all the VMs exceeds the total available memory of a single node. This would prevent all the VMs on a failed node from being relocated to the other node. We are in the process of procuring another box to add additional capacity to the cluster, however, in the meantime I wondered if I could prioritise certain VMs over others?
Using the "Recovery Policy" option in the luci admin interface, I can specify that some machines simply be disabled in the event of a failure and I have configured failover domains that prioritise which node VMs should be running on if both are up. However, what I would like to know is in the event of a node dying, is there is a way to stop specific VMs on the available node to allow priority VMs to be relocated there?
I have Googled about on the subject, but I can only find reference to the use of failover domains to prioritise which nodes VMs/resources can run on, as opposed to prioritising certain services over others.
Any information on this subject would be most appreciated!