Thank You.

... and yes - this is the problem with 'dedicated' SPARE drives - they just sit there unused and You never know if they will work when the time comes.

ZFS resolved that with DRAID where there are not 'dedicated' SPARE disks but 'spare block' spread across the disks:

- https://github.com/openzfs/zfs/wiki/dRAID-HOWTO/001b44728e1a...