I am running a truenes scale vm in proxmox with hba pass thru with 4x 12tb ironwolf, 4x 6tb wd red and 2x 4tb wd red all in there own mirror totally up to 80tb, How much memory should be allocating to this truenas scale VM …?
You also need to blacklist the HBA so that Proxmox can’t see the drives and then start to auto import the zfs pools it sees on the connected drives before the VMs start.
Be sure to verify that all those WD Reds are CMR.
SMR based drives, which WD Reds sometimes are, should not be used with ZFS.
How much RAM do you have? ZFS loves RAM since it caches data in it. I wouldn’t run 80TB with less than 32GB, but you can probably squeak by with the minimum 16GB. Less than so is doable but not definitely recommended, especially so if you have any inklings on the server doing more than basic file hosting in a limited way.