[SOLVED] Disk Rebuild successful, then parity check finds thousands of errors


Recommended Posts

Hi,

    I had a 2TB drive start reporting errors, so I took it out, ran a long SMART test on it, and although it had some errors on the drive, nothing seemed crazy and the error count wasn't going up when I ran the test again.  So, I wiped the drive using DD command, and then put it back in the machine and started to do a data rebuild.  Almost instantly many errors were being reported, so I stopped it, ejected the disk, and put a brand new 2TB hard drive in its place.

 

The data rebuild on the brand new drive took 24 hours, but it was successful and everything seemed great.  Feeling a little unsure though, I immediately ran a parity check after the data rebuild was successful, and during the test (only about a minute or two into it) I began to receive thousands of errors on the new drive that I just installed where the data rebuild was just done successfully.

 

So, any ideas on the problem?  I've checked the cables and cards (re-sat them as well), and everything seems to be fine.  I've been running UnRaid on this server since 2009 and haven't run into this issue before. 

 

I feel like this has to have been covered before in another thread, but I wasn't able to find it when I searched.  Any ideas are appreciated, and I can post a log later today, but just wanted to type this up now while I'm at work.  Thanks,

 

Nate

Link to comment

I did not, and now my options seem to be limited because it is thinking this disk is bad, hmmmm.  Without doing a new config file (because that will ruin the chance of having the data on this drive rebuilt), is there a way to make UnRaid forget about just this disk so I can re-add it to the array and pre_clear from the beginning?  I just noticed that the UDMA Error Count is 60 some thousand now, so I want to do a cable replacement and start over.

 

It's strange to me that if the cable is bad (looks fine and was inserted properly) that it would still be able to do a data re-build completely on a new drive, but then go crazy and report tons of UDMA errors on the parity.  Perhaps the read portion (i.e. pins) on the cable are bad? 

 

Strange, strange.....

 

Nate

Link to comment

I was never able to figure how to remove the drive from that database of UnRaid so that I could run a pre_clear on it again, as UnRaid was always seeing it as assigned to the array (even when it was unassigned), but since that is an optional step anyways, it wasn't too important, and it seems that the problem was actually a cable. 

 

The cable appears in fine condition, was not bent or twisted, was snapped in properly, but it seems to act up randomly (I'm guessing a weak or loose connection within) depending on the data conditions that the drive is experiencing. 

 

I always buy the cheapest cables I can, so I'm sure the build quality is terrible.  In a corporate environment I would choose name brand wiring, but in a home environment, I will probably continue to use the cheapies as this is the first cable issue I've had in >10 years.

 

Thanks for the replies.

 

Nate

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.