Having just upgraded my array to use fewer but larger drives, I am left with a stack of smaller, older ones. Since these drives have no business or confidential information on them, what steps would you take to prepare them for selling or passing to a family member? Do I simply format? Should I zero?

 

They are all currently sitting on the array in my Unassigned Devices group.

I would recommend running a pre-clear running only the write phase to zero out existing contents if you want to play safe.   However if you are absolutely sure there is no confidential information merely doing a format is probably sufficient.

Thanks. Since the drives are now likely to be sold rather than passed on to family (dad didn't want them), I will zero them using the middle part of the preclear tool.

Another thought for you since your family doesn't want them is - off line backup of your array.  I do that with my important data.  Since most is just media files and I can record it again I don't backup my most of my media files.  But it could take a considerable amount of time to acquire them again so I do backup some of the most important media files that I don't think I can easily get again.

It is a good suggestion but I actually have a second bank of four 8Tb drives going through preclear now.

 

In a few days I will have my main machine acting as the active NAS/VMs with the "old" NAS acting as backup. Both machines will have  4x8Tb and an SSD cache. The active machine will also have an NVMe in bare metal passthrough for the VMs.