I'm running unraid version 5.0rc11, had no problems before, but now when I run a parity check one of the drives throws up a lot of read errors over about 5 minutes or so mid-check; but no sync errors reported, and nothing particularly wrong I can see in the SMART report, but 204 errors showing on the drive in the unraid Main window. Syslog + SMART report attached.

 

I have just bought a new drive for expansion, should I just copy all the data off the drive with the errors and bin it? I'm assuming that all the data is currently ok if there's no parity errors...

 

Thanks,

 

 

 

syslog_errors.txt

smart_report.txt

I have this problem on one of my disks. I ran two parity checks (Correcting) and still getting read errors on one drive. Im now pre clearing another drive and I will replace it with this one but Im unsure if with the read errors if you can just stop the server and replace the faulty disk allowing the parity to rebuild the faulty one or if I should be copying the data off the drive to the others on the array.

I have just bought a new drive for expansion, should I just copy all the data off the drive with the errors and bin it? I'm assuming that all the data is currently ok if there's no parity errors...

Thanks,

 

I would.  Actually I wouldn't copy all the data ... I'd just replace the drive and let UnRAID do the rebuild.

 

My understanding of what UnRAID does when there's a read error is that it reconstructs the data (from the other drives and parity);  writes to back to the drive that had the error; and then reads it again.  If the read is successful, it's just a read error;  if the write fails, the drive is taken out of service (red-balled).

 

But if you're getting a LOT of these from the same drive, then I'd (a) check the cables to the drive -- reseat them (both data & power), and perhaps even change the data cable;  (b) see if that resolves the symptoms (i.e. run another parity check and see if it's "clean" now; and © if not, then I'd replace the drive.

 

Thanks Gary, I have checked all the cables and still getting 54 read errors on a Parity check. I will replace the drive as soon as the new one has finished the preclear.

Good plan.  If it's in warranty, I'd RMA the drive for a replacement.  If not, those are good drives to reformat and use for backups.

 

Yes it is but I'm going to replace all my drives with 6TB units one at a time now starting with the Parity.

Looks like a connection problem (bad or loose data or power cable) and not like a failed disk. Very unusual for a disk to fail with no sign in the smart report.

Thanks BJP - reseating connections and changing around cables (one or the other) has fixed it.

Glad it's working now.  As I noted earlier, when you get a lot of read errors from the same disk, it's very likely the disk just needs to be reseated (if in a hot-swap cage) or have the cables reseated or possibly even replaced. 

I tried that with mine but still no joy. It turned out to be a faulty drive.

Yes, the drive do fail.    I was just re-emphasizing that it's a good idea to first check the cables ... especially if you've recently done anything that could have caused any movement of the server [opened it to blow out the dust;  moved it at all;  even just cleaned the shelf it's on where it may have been "bumped" a bit.

 

Given that you've had a failed drive and need to replace it, I agree completely with your plan to start the move to 6TB drives.    No reason to buy anything smaller now.

 

Given that you've had a failed drive and need to replace it, I agree completely with your plan to start the move to 6TB drives.    No reason to buy anything smaller now.