V5-rc15: Dying parity drive

[EnKi]

Hi

 

I put my Unraid tower together probably around 7 years ago just as a safer way of storing the stuff I'd downloaded over the years. After setting it up and transferring the data across, it hasn't had a great deal of usage. It's normal state has been powered off, only being turned on when I wanted to copy files to or from it, which hasn't been very often.

During the last week or 2 I decided to hook it back up to my network to copy some files across to free up some space on my PC. Everything seemed to be ok but then I started to notice errors against the parity drive in the webGUI when copying across. I did a SMART check on the parity and the 3 data drives, the data drives were all fine but the parity drive had 1 reallocated sector and 44 pending. I ordered a replacement drive and started reading on how to replace the drive correctly. I read that it would be a good idea to do a parity check as a first step so I started the check. When I decided to give up, it had over 70000 errors against the parity drive, had corrected 441 sync errors, and had an estimated finish time of 235 days.

As it looks unlikely that I'm going to be able to do the parity check before replacing the drive, my main questions were:

- With over 400 sync errors and the parity check not even reaching 1% done, is it likely that my data is corrupted or are these errors only related to the parity drive itself?

- What would be the best way to move forward, assuming my data is ok? I'm thinking: upgrade to latest Unraid version, swap out the bad drive for the new, and then from what I've read over the past couple of days the new version of unraid will automatically preclear the new drive and rebuild the parity?

 

I've attached a syslog I grabbed before giving up on the parity check if it helps.

 

Thanks

syslog.txt

[trurl]

7 minutes ago, EnKi said:

parity drive had 1 reallocated sector and 44 pending

Yes that needs replacing.

 

1 minute ago, EnKi said:

I read that it would be a good idea to do a parity check as a first step

Where did you read this? If a drive is failing a parity check makes no sense because the failing drive can cause parity errors, and if replacing parity it also makes no sense because parity is going to be completely rebuilt on the new parity drive.

 

4 minutes ago, EnKi said:

from what I've read over the past couple of days the new version of unraid will automatically preclear the new drive and rebuild the parity?

Unraid will clear a drive when ADDing it to a NEW DATA slot in an array that already has valid parity. This is so parity will remain valid since a clear disk is all zeros and those zeros have no effect on parity.

 

Doesn't apply in your case since you are not ADDing a disk to a NEW DATA slot. Note that is the only scenario where a clear drive is required. Any use of preclear beyond that is strictly for testing purposes.

 

Just go ahead and replace / rebuild parity, then we can talk upgrade.

 

[EnKi]

That's great, I appreciate your reply.

When I originally put the tower together I had my head into it and had a better understanding, but that was a while ago.

I shall go ahead and replace the drive and rebuild the parity first, then I'll definitely have a look at this newer version.

Thanks for your time.

Edited April 29, 2020 by EnKi
Grammar