While it used to be closed source the maintainer a couple years back decided to not make it a job, and open sourced, took down the hosted option, and nowaintains it as a side project open sourced.

Both Ubuntu and mint are debian based.

Sync the internal drive cache with the disk. IIRC

That assumes you don’t value your time spent dealing with troubles that come.

Like the other person said, it’s fine if you don’t, but for me it’s worth a little upfront cost to have to deal with less ordering new drives, putting the drive in the server, monitor rebuilding of the array, ect…

None of that is an excuse for lack of proper backups. Because even new drives can fail catastrophically.