Can I add a disk to my RAID 4/5 SoftRAID array?

In short, the answer is ‘no’.

While you can add a disk to a RAID 5 array to replace a missing, failed, or otherwise removed member disk – you cannot add to the total number of disks included in your SoftRAID array. This is a feature under investigation for a future release.

Increasing the number of drives total in the volume will require that the volume be first deleted and then re-created including the new member drive(s). As expected, this is data-destructive, so make sure any data currently on an array that you would like to keep is backed up elsewhere before performing this process.