>>What's the collective thought, is my datastore toast?
RAID6 can only sustain two concurrent disk failures at a time without data loss. If a third disk fails in an array, you are typically facing total loss of data.
>>Is it worth updating to 6.7 to run VOMA in fix mode?
It's unlikely to make a difference since you're facing a failure mode (three-disk failure) that software, generally, cannot fix.
Depending on how far along the rebuild completed before the third disk failed, you may be able to pull some data off the array using software-based data recovery tools on the part of the array that completed rebuilding. This can be a time-consuming process and may only provide you with shards of actual data.
>>Should I just put the beast out of its misery, blow the array away, and start again, restoring whatever backups I've got?
If you have known-good recent backups, and getting the system back online quickly is important, then restoring from backups is probably the best option. However, if you're concerned about data which has not been backed up and may still be on the damaged array, restore to a different storage server/NAS/etc. and then perform data recovery on the damaged array (ymmv).
I've gathered the file, it's in my Google Drive.
The forum doesn't seem to be allowing me to send you a DM with the link - is there another way I can get it to you?
Sorry to hear that - is skype not allowed in your country ?