I’ve been running VMs on some old DELL T110ii but realise that I’ve loaded it a bit too much so want to leave it doing the job of NAS with Truenas Scale and move all my VMs to Proxmox. The idea is that I would have two optiplex that provide redundancy. Truenas Scale has got me used to ZFS but clear may not be an option with Optiplex 3020 as ZFS is pointless with one SSD. Has anyone got some similar arrangement and has their VMs and containers running on these simple desktop machines? How are you managing high availability and resilience?
What’s high availability to you? There’s an increasing cost.
Anyway, I have a similar setup. NAS for storage and OptiPlex Proxmox nodes for compute. But I went a different route and set up an iSCSI SAN and all the guests use block storage on the NAS. Guest backups by Proxmox go to file storage on the NAS and backed up to a second NAS.
Contrary to a lot of posts that I have seen, I would say ZFS isn’t pointless with a single drive. Even if you can’t repair corruption with a single drive knowing something is corrupt in the first place is even more important (you have backups to restore it from right?).
And a ZFS still has a lot of features that are useful regardless. Like snapshots, compression, reflinks, send/receive, and COW means no concerns about data loss during a crash.
BTRFS can do all of this too and I believe it is better about low memory systems but since you have ZFS on your NAS you unlock a lot of possibilities keeping them the same.
I.e. say you keep your T110ii running with ZFS you can use tools like syncoid to periodically push snapshots from the Optiplex to your T110.
That way your Optiplex can be a workhorse, and your NAS can keep the backup+periodic snapshots of the important data.
I don’t have any experience with TrueNAS in particular but it looks like syncoid works with it. You might need to make sure that pool versions/flags are the same for sending/receive to work.
Alternatively keep that data on an NFS mount. The SSD in the Optiplex would just be for the base OS and wouldn’t have any data that can’t be thrown away. The disadvantage here being your Optiplex now relies on a lot more to keep running (networking + nas must be online all the time).
If you need HA for the VMs you likely need distributed storage for the VMs to run on. No point in building an HA VM solution if it just moves the single point of failure to your NAS.
Personally I like Harvester, but the minimum requirements are probably beyond what your hardware can handle.
Since you are already on TrueNAS Scale have you looked at using TrueNAS Scale on the Optiplex with replication tasks for backups?