Yes, the docs[1] tells you to match the redundancy level of the pool, but you could technically do something else. Note the docs say level and not type. So if

Yes, the docs[1] tells you to match the redundancy level of the pool, but you could technically do something else. Note the docs say level and not type. So if you have raid-z1 the a mirror would be appropriate as they both tolerate losing a single disk, and if you have raid-z2 you can use a 3-way mirror etc. [1]: https://openzfs.github.io/openzfs-docs/man/master/7/zpoolconcepts.7.html#special https://openzfs.github.io/openzfs-docs/man/master/7/zpoolcon...