If I configure a zfs mirror outside the array, will it get the same data integrity benefits from zfs as on any other zfs pool? There are some discussions on limitations on Unraid's zfs implementation around the forums and Reddit. But the way I read them, its about when you use zfs for individual drives in the Array?

I'm considering a zfs mirror for my photo collection, which is the most valuable and irreplacable data I have, and storing the rest on Unraid's Array.

Can Unraid spin down zfs pools like it spins down the Array? My "photo pool" will be used only when I do active work with my photos, so want that pool dormant most of the time.

And finally, I if configure a zfs pool like that, I could also use that as a snapshot destination for my cache, which is also a zfs mirror. I wonder if that would mean I would dare to go with a single NVMe as my cache? My motherboard has 8 SATA ports, one m.2 slot, and one PCI x4. But because of shared lanes, when I use the PCI x4 for a NVMe adapter, like I do, I can only have 4 SATA drives. Should I go with Array + zfs pool, I would be limited to two drives in the array.

10 minutes ago, thoresson said:

If I configure a zfs mirror outside the array, will it get the same data integrity benefits from zfs as on any other zfs pool?

Yes.

Excellent! That allows for a great middle-ground for me: zfs for my most important data, where I also can make a better prediction for my storage needs, and the array as a backup target and some other use cases where guessing future need is harder!

Edited July 3, 20251 yr by thoresson