Using Mercury Elite Pro Quad as a Time Machine drive and SoftRAID with BigSur
@softraid-support 6.0.4 b5 gives this error:
RAID Level Not Supported
You are trying to use a RAID level which is not supported by your SoftRAID license. The SoftRAID Lite license only supports stripe (RAID 0) and mirror (RAID 1) volumes.
I went ahead and bought the license (SoftRAID 6 XT for OWC Enclosures), but you can't enter the serial number in the beta... downgraded to 6.0.3, entered the license and then uninstalled and reinstalled the 6.0.4 b5 and still get this error.
@softraid-support OK, in the meantime, I went ahead with 6.0.4 b5 and formatted the drive as APFS through SoftRAID and made it a RAID 1 volume. Testing a Time Machine backup in that mode. I realized everything done to this point has been RAID 5, which is what I want, but want to rule out that it's not an issue with RAID 5.
Do you have another startup volume, that you can start from and run Disk Utility "first aid"?
I don't know why your Time Machine is not working.