But I’m wondering if there is anything to gain from using RAID 1 equivalent to host a repository?
I’m considering using Drivepool as a repository target because it allows for growing the storage to any size with any number of object duplications. The advantage to using Drivepool WITH Kopia is effective deduping before storage. Cuts down on waste.
Currently performing a complete 8TB restore from a local repository to a local drive. 3ea errors so far @~6TB restored.
I don’t understand your question, since Kopia is in no way related to the underlying storage. Drivepool looks like a volume manager to, same as LVM or ZFS on Linux. In what way Drivepool’s performance is better than any other available volume manager, I don’t know.
However, I like the storage “device” my Kopia repos reside on to be as simple as possible and rather go for a 2nd (cloned) repo for redundancy. In the end, no matter what happens to your Drivepool device, it’s still the only copy of your repo…
As far as RAID types go, I’d use RAID1 or 10 for simple redundancy with reasonable speed and higher RAID types for more resilient redundancy at the expense of read/write performance. But… I’d only ever use RAID1+0 for operational data and not archive/backup data.