"Disk in parity slot is not biggest." after a power failure

[mappo]

I have 5 identical WD REDs, each 4TB. Three of them are data disks and two are parity.
Everything was working fine.

Then I installed Unassigned devices and attached a 5 TB USB drive with old photos and phone videos.
Everything was still working fine ... until we lost power.

When the system re-booted, the USB drive was still attached - and still larger than any of the parity drives.

This resulted in the "Wrong" error. After some research on this forum, I unplugged the USB drive and used Tools\New config.

This resolved the "Wrong" error, but the array remains stopped. The START button is no clickable and next to the "Stopped" is a green dot and the message that "Disk in parity slot is not biggest."

 

I've read in previous ports that this might be caused by the controller. In my case, all five drives are connected to SATA ports on the motherboard and it has worked fine for a couple of weeks.

[JorgeB]

Please post the diagnostics.

[mappo]

3 minutes ago, JorgeB said:

Please post the diagnostics.

 

batcave-diagnostics-20240212-1905.zip

[JorgeB]

43 minutes ago, mappo said:

This resulted in the "Wrong" error.

This wrong disk error you mention, was it showing for all array devices? And was this the first time the array was restarted after the array disks were initially formatted?

[mappo]

Yes, it was reported on all three data disks - but not on the parity disks.

I'm not sure, but it might very well be that the power outage was the first shutdown for the array. I'm gonna say Yes.

[JorgeB]

OK, you are likely running into a bug, even if we fixed the parity issues all disks would show up unmountable, type this for all 3 data array disks:

 

sgdisk -o -a 8 -n 1:1M:0 /dev/sdX

 

Replace X with correct disk identifiers, as of last diags they were /dev/sdc, d and f, but they can change with a reboot, so double check.

 

Reboot, all 3 array data disks will show as wrong again, do another new config and check "parity is already valid" before starting the array, start the array and everything should be back to normal, if it's not post new diags.

 

 

 

 

[mappo]

I executed the command for all three drives.

Rebooted.

Like you predicted, the array remains stopped but the START button is clickable.

However, I'm unable to perform the New config. No matter which combination I select in the drop-down, the APPLY button stays inactive. Next to it is the message "Array has been Reset (please configure)".

 

Should I go ahead and START the array with "Parity is already valid." checked?

I've attached new diag. logs.

batcave-diagnostics-20240212-2025.zip

[JorgeB]

1 hour ago, mappo said:

However, I'm unable to perform the New config.

Yep, this was my bad, you couldn't start the array before, so all disks are already new, just check "parity is already valid" and start the array.

[mappo]

That seems to have fixed it. Thank you @JorgeB! Now, a few questions.

 

What can be learned from this? What did I do wrong? Was it a mistake to boot the system with the USB drive still attached?

And, most importantly: what did the magic spell command actually do?

[mappo]

Answering my own question here while also letting others know about this great page I found:

https://explainshell.com/explain?cmd=sgdisk+-o+-a+8+-n+1%3A1M%3A0+%2Fdev%2Fsdc

[JorgeB]

11 hours ago, mappo said:

What did I do wrong?

You didn't do anything wrong, it was caused by a recently discovered bug, though the initial new config you did wasn't going to help in this case, and it prevented us from being 100% sure it was this bug, so just recommend asking for help before trying solutions found on the forum, because sometimes the symptoms can be similar but have a different root cause.