It will be controlled by Truenas not Proxmox. Truenas can add swap space to each drive automatically: https://www.ixsystems.com/documentation/truenas/11.3-U2.2/storage.html

But you probably already have existing drives so that doesn’t help. This might though: https://wiki.debian.org/Swap

But be aware that Truenas is design to be an appliance and doesn’t really want you tinkering under the hood. So you may have to manually add the SWAP after each boot of TN.

I would guess the best long term fix would be moving services out of the TN VM and into a different VM.

I have TN Scale VM hosted in Proxmox. The only “issue” I have is the webgui gets pushed to SWAP if not used for more than a week. So when I connect it it literally takes a couple minutes while is gets shuffled back into RAM. Once it’s “warmed up” it’s fine. But my Scale VM is doing these things: manage ZFS pools, control NFS/Samba shares, replicate pool snapshots to off-site backup server. It intentionally have it do nothing else. All other services are in different VMs or LXC containers in Proxmox.

Does your Scale install have any SWAP space setup? That should prevent out of memory issues. Potential performance issues would be better than crashing.

I can understand the potential problems of trying to define “low-effort post”. In contrast can guidelines be given for a “quality post”. If no guidance on either end is given it may discourage some people from posting anything. Maybe people can contribute what they see as indications of a “quality post”.