Title basically. I have like 7tb of data on my current raid array, and in the future, I plan to wipe it and make it ZFS, with 3 additional 7tb drives. I'd like to not lose all the data. I'm sure I can't be the only one who has this issue. What do you guys use for temporary backup solution, while repurposing your HW.

My current server runs Ubuntu server bare metal. I'm thinking of running Proxmox, than VM of TrueNAS, for ZFS, sharing the storage pool across, what would than be a Proxmox cluster of 2 machines (potentially a 3rd in the future). I think that this is probably the best way.