One big VM - HA

[Ulrar]

Hi,

We have a cluster with 64 Gb or ram hosts. We need to create a VM with about 60 Gb of ram, the question is can HA work with this ?
In the event of a host failure, I can see two options :
- We have some VMs everywhere else, so there is nowhere with 60 Gb free and some live migrations will be
needed to "free" that up, moving VM around to liberate 60 Gb of ram on one host.
- We left, on purpose, a whole node free for this somewhere, will proxmox be smart enough to reserve that host for that VM or could it move some other smaller VM on it at some point ? Not sure how proxmox decides which VMs move where when a node fails, it looks a bit random.

The other solution is to just not put the node in the cluster and just install the system on it directly, not doing a VM. Since a whole server will be used by that machine, if HA can't work, no use in doing a VM for it I guess.

Thanks !

 

[micush]

I have done exactly this.

Create a new HA group. In that particular group only put the hosts that can manage the VM.

Then add the VM to HA, selecting this newly created group.

In the event of failure, HA will only move the VM to the hosts within the specific group.

 

[Ulrar]

Thanks for the answer.
If I understand it correctly, it means that no other VMs will be able to fallback to these nodes, right ?
So it's basically like having an HA cluster inside the cluster ?

 

[micush]

Only the VMs assigned to a specific HA group will be able to use the hosts that belong to that HA group. It's probably easier to think of it as partitioning the HA cluster into different groups of hosts.