As I remember ZFS did recently just add the ability to grow an array, but it's not seamless and wastes space because of some limitations with it. You also need to learn the CLI procedures to do it without breaking something, vs just clicking a button on a webUI.
ZFS also recently had a major data loss bug so I'm not sure safer is accurate.
I do use ZFS on my servers, I'm not actually an unraid user myself. But managing ZFS is not easy and takes a lot of time to learn.
Lots of backup software out there, I use a mix of Veeam Endpoint, Restic w/ Backblaze B2, and iDrive.
Are you trying to add it to a VM or a CT?
You can bind mount a folder on the host into a CT: https://pve.proxmox.com/wiki/Linux_Container#_bind_mount_points
For a VM you have to either add a virtual disk image on the external drive (will be fixed size, cannot use existing data), or share the folder on the host via NFS and mount it in the VM with the NFS client.
Unraid can use randomly sized disks, and allows expansion of an array by adding more disks. Something that traditional RAID doesn't do.
It's more like Synology but on your own hardware, much more user friendly for people that don't have the experience (or time) to set it up the hard way.
It's much simpler/easier to use, and supports expanding storage by adding more drives. More like your typical user friendly NAS like Synology.
TrueNAS can give you almost the same end result (minus being able to expand storage easily), but just takes a lot more experience and knowledge to pull it off.
I'm just impressed an SD card in a Pi lasted since 2017 without losing all your data on its own.
For the future the general guideline is 3 copies of your data at minimum, so definitely set up some backups.
Yeah they don't mention it at all which is a bit concerning.
A lot of live images will run entirely from RAM, flash drives are typically quit slow so it makes the experience much nicer.
They've gotta make money somehow.
Having a bunch of intentionally out of date systems seems like a bad idea though.
Very odd, I think something else is going on not related to LXC/Proxmox. I've got LXC containers with external mounts and internal storage and haven't seen any data loss over the years they've been running.
With the GPU in there I would guess in the 50-100W range.
Not the same, as it doesn't make an image of the system.