Thanks for taking the time to read and comment. I'm looking to backup a zpool of media. I had tried to setup a truenas for the data but I didn't love the UI and I have what I need on Ubuntu with docker. My plan is to destroy a zpool of the truenas made of 4x10tb raidz1 and move that pool into the primary server (add a pcie with more sata ports) then use zpool attach to mirror my current 4x8tb raidz1 (mnt) to the newly recreated zpool of the 4x10tb from the old truenas server (named mntbackup). So zpool attach mnt to mntbackup. Sounds like this automatically starts mirroring.
I know this isn't ideal without being an off-site backup but I'm not the most literate at actually managing this and want something easy. Would I be able to just plug in backup, then unplug the backup pool and cold storage? I don't need perfect redundancy. Would I be able to plug the mntbackup raidz1 back in sometime in the future and the missing new data automatically sync or would I need scripts of rysnc or zfs send receive to add new data?
Thanks for any insight and help!