Jan Kuźniak

In my case I was able to rebuild the file system -- but got all the files in "lost+found" (I just hope I recovered all the files - it's sometimes hard to find what's missing). I'm guessing that means I got some minor corruption / out of sync on the first slightly-failed disk and the parity was able to recover almost everything. I am unfortunately not able to comment on your case further.

Seems to have worked, you're my Hero! I'll attempt recovering the data and let you know how that went.

Yes, that disk was XFS. And here's an odd one - it wouldn't let me change the FS - the "apply" option is grayed out... Also, when I start the array in the maintenance mode, the "check filesystem status" section is missing. I'm tempted to try formatting the spare drive to XFS and re-doing the new config trick you posted at first - maybe that would fool the array into emulating the original FS? (double checking with you guys before I irreversibly fuck something up ;-))

Hi guys, reporting from the front line. JorgeB: Your method worked - and didn't work at the same time. I was indeed able to start an array in maintenance mode while marking parity as good, get unRaid to accept Disk 2 as valid and then make it so that it shows it's emulating Disk 1 when I removed the replacement drive. Unfortunately, it can't mount the emulated disk and it wouldn't show up in the devices - so I can't even run a filesystem check on it. Am I missing something obvious? See screenshot below.

Thanks JorgeB, I'll give it a shot. I was thinking unRaid wouldn't let me start the array with Disk 1 replaced and Disk 2 disabled - I'm glad that's an option. Keep your fingers crossed and I'll keep you posted.

Yes, a new disk will not be a problem. If you wouldn't mind posting the instructions, that would be an invaluable help.

Unfortunately, I am confident the Disk 1 is dead - I did the usual cable / port juggle (including power cable), booted the machine with just this drive attached (to isolate power delivery problems) etc. It did show up once, early in the process, but only for a short time and only to disappear for good on the following attempts. The original question remains: is there a way to force Disk 2 from enabled to disabled (without rebuilding) so that I can start the unRaid array and recover Disk 1 using the parity.

Right, sorry for omitting this one - I blame the "my nas broke" panic mode. Please find the diagnostics attached. nas-diagnostics-20210720-1822.zip

Hello! I've got an odd one today. I've got a server with 1 parity 1 cache and 4 data drives (2x 2TB, 1x 3TB and 1x 6TB). Now that happened: * One of the old 2TB drives (Disk 2) had write errors and got disabled. * When I wanted to rebuild it, the other one (Disk 1) died hard (read errors, "missing" in unRaid). * I am able to read the data from the disabled drive when I mount it; I trust it and assume it was a loose cable issue. I am (understandably) unable to start the array in a normal mode - but I would love to temporarily "force" it to start by clearing the "disabled" flag on Disk 2 without rebuilding it - so that I can emulate Disk 1 and recover the data from parity. Is there a way to do that (e.g. by manually changing a config file / database) or am I too optimistic in my assumptions and basically just lost the Disk 1 data? Thanks in advance for any insights - even if those are to confirm my worry that an out-of-unRaid recovery is my only option.