On June 17, 2021 4:47 pm, marcos negrini wrote: > Hello:I am administrator of a proxmox cluster and I have been testing High > Availability, and I am very satisfied with the performance; but I wanted to > understand a little more in depth how the memory management works. I did the > tests in a cluster of 3 servers with a SAN storage, I tried to cut the power > to a physical server and almost instantly the vm's that were configured with > HA went to the next node, my question is, how do you manage the memory of > each vm's? do you pre-share it in the other physical servers so that the > memory status of each one is not lost? how do you manage the loss of the > information that was not copied? is there any technical document of this > implementation in proxmox?Regardspd: sorry for my english level, I hope my > doubt is interpreted.
I'd suggest reading [1] as a starting point. To answer your questions: - guest memory is not replicated or shared between nodes, HA just tries to ensure the guest is running "somewhere" according to the HA configuration - ideally your guests' volumes are on shared storage, but if you can live with losing data since the last replication, ZFS with replication can also be an option - if a node disappears/crashes/loses quorum/.. it gets fenced, the still quorate part of the cluster will notice and "steal" the affected HA resources -- if the fenced node is still responsive, it's watchdog timer will expire and it will shutdown (stopping all running guests in the process) -- the stealing node will wait a certain amount of time to give the fenced node time to be completely fenced, then it will take over the guest configs and start the guest - additionally, you can configure what should happen to HA resources on (orderly) node shutdown/reboot (see "Node Maintenance" in the admin guide) - here one of the options is to migrate them to other nodes, which is possibly what you triggered in your test? 1: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#chapter_ha_manager _______________________________________________ pve-user mailing list [email protected] https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-user
