Parity disk disabled after another disk was unmountable

[Alby24]

Hi there, 

 

I'm having issues with my Unraid server.

Yesterday, Disk 4 reported an UDMA CRC error count equal to 1. The array was working fine.

Today, when I booted the system up, the UDMA CRC error count of Disk 4 was increased to 9 and the Web UI was saying that the drive was unmountable. Most importantly, the parity disk was automatically disabled. 

After a reboot, Disk 4 was successfully mounted and present in the array, however the parity disk was still disabled.

 

I'm aware of the fact that UDMA CRC error count is related to connection errors, therefore I am planning on checking the cable of Disk 4.

What concerns me is that I have no clue why the parity disk, which seems healthy, was randomly disabled.

It also says that the array is unprotected.

 

What happened to the parity disk? How do I re-enable it?

I'm attaching the diagnostic.

 

P.S. I find unbelievable that there is no explanation on the Web UI on why the system decided to disable a working drive.

 

unraid-nas-diagnostics-20230311-2025.zip

Edited March 11, 2023 by Alby24

[itimpi]

3 minutes ago, Alby24 said:

I find unbelievable that there is no explanation on the Web UI on why the system decided to disable a working drive

A drive is disabled when a write to it fails.

[Alby24]

Thanks for your answer.

 

5 minutes ago, itimpi said:

A drive is disabled when a write to it fails.

That's good to know, it should be stated in the UI somewhere.

 

Given that the SMART report of the parity drive seems ok, is there are a possibility that there was a write failure due to the fact that Disk 4 was unmountable?

[itimpi]

Just now, Alby24 said:

Thanks for your answer.

 

That's good to know, it should be stated in the UI somewhere.

 

Given that the SMART report of the parity drive seems ok, is there are a possibility that there was a write failure due to the fact that Disk 4 was unmountable?

Not directly.  It is a write to the drive that got disabled that failed (I.e. the parity drive).   In theory the drives should be independent but maybe something happened that affected multiple drives.

[Alby24]

1 minute ago, itimpi said:

Not directly.  It is a write to the drive that got disabled that failed (I.e. the parity drive).   In theory the drives should be independent but maybe something happened that affected multiple drives.

What to do now then? How do I re-enable the parity drive?

[JorgeB]

https://wiki.unraid.net/Manual/Storage_Management#Rebuilding_a_drive_onto_itself

[Alby24]

Two days later, this is what I've done:

• I've changed the cable of Disk 4 and never encountered any other error
• I've rebuilt Parity disk onto itself (lol) and never encountered any other error

In short, Disk 4 was unmountable because of the cable, and the parity disk was disabled because Unraid said so.

[Alby24]

I wanted to add something outside of what I marked as a solution.

 

Basically, the issue was that Unraid decided that my parity disk had problems when it hadn't.

Just because one single write failed, it decided that the disk was dead and therefore disabled it.

By doing this, the array was put at risk, once again, for no reason at all.

Unraid should've been built to protect your data, instead it tried to temper with it like a malware. This is terrifying.

 

Disabling a drive just because one single write failed (that could happen for a loooot of reasons) does not make any sense and I hope you all see that.

Run a check on that sector and keep the drive active.

If write operations fails frequently, then you can think about disabling the drive.

 

I am growing tired of the lack of documentation, of the lack of official support that this (paid) software has.

In fact, this forum was not able to provide any concrete solution and help outside of something very basic and, to be precise, 90% of my post was just ignored.

 

I really cannot recommend Unraid anymore, unless you want to risk losing your data without any failure and want to troubleshot it with a UI that gives out useless messages only.

Edited March 13, 2023 by Alby24

[itimpi]

3 hours ago, Alby24 said:

I am growing tired of the lack of documentation

Have you read all the online documentation?   Not sure what you think is lacking so mentioning where you see the omissions might lead to those parts being improved.