trurl

OK, original parity SMART looks OK. Forget about New Config for now. Can you assign that original parity to parity slot, and assign nothing to slot2? If it offers to rebuild parity, don't start the array. If it doesn't want to rebuild parity, start the array and see if you can see the "emulated" disk2 files. The emulated disk is exactly what will be rebuilt when you assign the new disk to slot2.

Have you tried with a USB 2 port? Not sure it matters when creating the flash on another computer, but I do know many people have problems with flash booting Unraid in a USB 3 port. Also, are you sure there is only one partition on the flash?

OK, let's proceed without the original parity and maybe later you can see if it can be made to work. Maybe it really did just decide to die at this inopportune moment. Go to Tools - New Config, assign the original disk2 to slot2, and the new disk to parity. Starting the array will begin parity rebuild. If it offers to format anything, DON'T.

If we could get SMART for parity and it turned out to be OK then you could just proceed with your original plan. Check all connections, SATA and power, both ends. Make sure to check any power splitters along the way. Then post another diagnostic. If there really was a problem with parity, Unraid may have been able to tell you this before you tried to replace the other disk. Did you check the Dashboard for any SMART warnings? Do you have Notifications configured to alert you immediately by email or other agent when Unraid detects a problem?

Your screenshots aren't working. Now that you have been approved, you should be able to attach them directly to your NEXT post. In future, please always attach instead of linking to an external site.

Have you done memtest? Have you tried SAFE mode? This may be the root of your problems but I don't know how you could have gotten to that state. I am going to ping @johnnie.black and see what he thinks is the best way to proceed to get your cache pool fixed.

I assume you mean WD-WCAZA0850387. It is not actually assigned to any slot. That disk looks OK. I guess you were only replacing it in order to upsize? Is your original parity ZA1AGKMJ? I see it briefly in syslog but it can't really communicate and there is no SMART for it. Could just be a bad connection. Post a screenshot of Main - Array Devices just to make sure I fully understand what you have now.

That diagnostic was taken just after reboot and without the array started. Start the array and post a new diagnostic. Please attach directly to your NEXT post instead of linking to an external site. Also, go to Settings - Syslog Server and set it up so the syslogs can be saved for access after a crash and reboot.

Parity is not showing up in Diagnostics so I don't know for sure if it is bad or not, but it doesn't really matter. What I would really want to see is SMART for the original disk2. Can you plug it back in and post new diagnostics?

I think you should be able to simply assign the original drive to slot2, and the new disk to parity, and then start the array to begin rebuilding parity. If it complains about that then maybe you would have to New Config to get the assignments like you want. But it shouldn't matter since the end result will be to rebuild parity, which is what you want anyway. It is only if you were trying to get it to rebuild a data disk that you would have to do something more complicated.

After looking at your diagnostics, it seems you have already assigned the new disk to slot2. Have you actually started the array?

Haven't looked at the diagnostics yet. OK. That isn't the way I would normally use the term "remove" when speaking about the array. If I said I removed a drive, I would mean I had shrunk the array by New Config without the drive and rebuilt parity. Until there is an actual change in disk assignments the drive hasn't been removed in any sense. It is not strictly necessary to unassign the old drive. Simply assigning the replacement to the same slot and starting the array will begin the rebuild. If you have not yet assigned the replacement, then as far as Unraid is concerned, you can simply assign the old drive back to the same slot and start the array.

This is probably nothing to do with this specific docker so I may split to its own topic. Go to Tools-Diagnostics and attach the complete Diagnostics zip file to your NEXT post.

Also, go to Tools-Diagnostics and attach the complete Diagnostics zip file to your NEXT post.

Just to make sure there is no misunderstanding, what exactly do you mean by "removing it from the array"?

Go to Tools-diagnostics and attach the complete Diagnostics zip file to your NEXT post. Also, go to Settings-Syslog Server and configure it so your syslog will be saved where you can get it after rebooting.

Should be fine for NAS only. If you want dockers or VMs more would be good. Maybe not enough CPU to go very far with that though.

For example: https://forums.unraid.net/topic/70252-supermicro-aoc-sas2lp-mv8-8-port-sassata-compatible-with-unraid-6/ I don't think you mentioned, how much RAM do you have?

Go to Tools - Diagnostics and attach the complete Diagnostics zip file to your NEXT post.

Technically there is no need to run a parity check. Parity is already valid. The only reason you might want to run a (non-correcting) parity check would be to confirm that the rebuild is completely valid.

And, of course, you can always just get rid of the credential in Control Panel - Credential Manager and it will have to start over with a new credential. But, another thing to remember is that it will always try with the credentials of the current Windows user before it even asks. And if that succeeds, that becomes the credential used for all subsequent access.

This is the part that is always confusing. Windows networking basically assumes there will be only one credential used from one machine to another machine. Once it has established that credential, it won't use any other. When it fails to access a share which requires another credential, it throws up the login because it failed, but it doesn't actually do anything with that login. One way you can fool Windows into using a different credential is to try accessing by IP instead of name (or by name if you were using IP). It keeps those credentials separately because it thinks of them as different machines it is trying to access.

No, it is not possible to remove a disk without rebuilding parity, and of course, rebuilding parity would make it impossible to rebuild any data disk. At this point, I think we can forget about rebuilding anything since it seems extremely unlikely parity is even valid. If he ran with a missing disk for some time he hasn't even been able to do a parity check, since parity can't be checked in that state. All it would do if you tried is a "read check", which doesn't do anything except see if the disks can be read. New Config is going to be the way forward. Probably disk2 is OK. Maybe we can get some data from the original disk1. It doesn't sound like any of the other disks are expected to have any data. I can only assume disk3 was added with New Config, since otherwise it wouldn't let you add a disk to a new slot when you already had a missing disk. Possibly disk3 is unmountable because it was never formatted and so has no filesystem. @beno, you didn't actually answer this question:

And your screenshot is showing the array as started, which also brings up the question of disk3 and how you got here, since in your first sentence you seemed to imply there was only 2 data disks. Did you ever go to Tools - New Config when you were stumbling around? Was there any point in any of this where you rebuilt parity?

There are 2 other "disks" listed in SMART in your Diagnostics, but they aren't reporting anything except: /dev/sdb: Unknown USB bridge [0x05e3:0x0729 (0x405)] Are you trying to use USB connections in your array?