... As I was thinking about that issue, I thought of a possible way to force a rebuild without the intervening parity check.

 

I am NOT sure if this will work -- but you could TRY this (shouldn't hurt anything to try it) ...

 

(a)  Do a New Config, setting everything the way you want it, but do NOT Start the array.  Also be sure Auto-Start is NOT enabled.

 

(b)  Shut down and physically disconnect the drive you want to rebuild (so it will be missing when you start the array)

 

©  Boot; check the "Parity is already valid" box, and Start the array.    Since a drive will be missing, it shouldn't start a parity check.

 

(d)  Stop the array; assign the replacement drive to the slot; and Start the array.  Hopefully this will cause a rebuild to start.

 

I am NOT sure if this process will work -- but if it does please note that here so we can suggest it for similar cases until (hopefully) the "Trust Parity" option is modified to the automatic check does NOT start up.

 

I believe this will not work because if in step (a) you don’t start the array the new config won’t be saved, next time you power on all disk assignments will be empty.

 

You could temporarily load Unraid 5.0.6 to do the new config, the trust parity option does not trigger the parity check, then reload v6 to continue the rebuild process, I tested this on my test server and it worked but I probably would not use it in server with data as results may be unexpected.

Unfortunately it didn't work.

jonnie was correct. I even tried to start in maintenance mode as a first step thinking it would not mount any of the drives as a precaution. By the time I was able to stop it I had 7303 parity writes.

 

I ended up popping in a replacement drive and starting from scratch with a 'new' array.

I mounted the 'broken' drive outside the array and once the initial parity is rebuilt (protecting the rest of the array) I'll copy the data back over from lost+found and run a crc check on it vs the backup data.

 

Thanks for all your help. I really appreciate the support you provide this community when things go south.

I'll open up a new thread for Tom asking that 'Trust My Parity' actually does so.

This is now the 4th case I can remember that has been unable to do a simple drive rebuild that would have easily worked fine if "Trust Parity" actually TRUSTED parity.

 

You simply can't CANCEL the check fast enough to prevent damage -- as you noted, you had 7303 "corrections" in the brief time it was running ... and all of those are in the first part of the disk, where key formatting and directory information is stored, so the drive reconstruction won't work properly.

 

Hopefully the "Trust Parity" option [e.g. the "Parity is already valid" box] will be fixed so it does not start that check.

 

I've already got a feature request thread on this -- I'll add another post pointing to this thread to reinforce the damage it's causing ... you might want to add a comment there as well.