Can I use SoftRAID with Time Machine?
Any time you connect a disk containing a SoftRAID volume, or create a new SoftRAID volume, Time Machine will ask if you want to use that volume as a Time Machine target. Note that the volume has to be over a certain size (big enough to back up your data), or Time Machine will ignore it.
Mac OS will ask you when you first create any new volume—whether with SoftRAID, Disk Utility or another program—if you want it to be a Time Machine volume. Just select “Use as Backup Disk” and Time Machine will back up to that volume.
If at any time you want to add (or remove) a connected SoftRAID volume as a Time Machine target, you can do so by going to Time Machine in System Preferences, and using “Select Backup Disk” to select your volume. (Note: even though Time Machine says “Select Backup Disk” it’s really the volume on the disk that’s being used for the backup).