How to achieve distribution of a cohort of vms across more than one host?

[wolfspyre]

howdy all!

I've dug thru the forums here, but haven't found much that speaks directly to my challenge.

I have a 6 node proxmox cluster.
4x dell r730xd
2x dell r720xd (in the process of moving to 730's... but been slow in migration)
I have a few pools of HA VMs ...
ie
a pair of webservers...
a triad of ci runners...
a pair of VMs running HA mysql
a pair of VMs running ha postgres
a pair of VMs running ha redis

what I'm trying to determine is how to express to proxmox that I would like to inject an aversion to schedule multiple vms of the same pool on the same physical host, to achieve wider resource distribution.

I understand I can associate a weight with a phyiscal host to bias a pool towards, or away from that specific hardware...

but I don't see a mechanism to express how densely or loosely to leverage the hardware available to the pool.

there are certainly scenarios where binpacking vms into a tighter hardware footprint is preferential

likewise there are scenarios where one would prefer to have the VMs inclined to live on different hosts, but are not precluded from cohabitation if necessary...

how can I tell the proxmox ha scheduler:

in a perfect world I would like the VM members of pool A to be deployed on divergent hosts.
however, if necessary, they **MAY** cohabitate.

 

[waltar]

in a perfect world I would like the VM members of pool A to be deployed on divergent hosts.
however, if necessary, they **MAY** cohabitate.

Don't really understand your problem as you already said you can associate a weight with a phyiscal host to bias the vm's.
We have a ha group to each node with prio set to number of nodes, eg prio 6 to node groupname itself. The other hosts (5) can get staggered prio down for second, maybe third and last run prio. So if you generate a vm or have your vm's just give each with the ha group a "homehost" and your your perfect world is reached (which we do so also).