I'm new to unRAID and still evaluating, so appreciate any help the forum can provide in educating me.

 

I was running a routine parity check and I got a bunch of read/write errors from Disk 6 (sde). unRAID took the drive offline and I wasn't able to obtain a SMART report. Attached is my diagnostic log from the morning after the parity check that produced errors.

 

I opened the case this morning and replaced the SATA cable that was used for Disk 6, and decided to also swap SATA ports on my MB with another drive.

 

Upon powering up the server it still showed a Red X next to Disk 6 (now sdi instead of sde), but I was able to obtain a SMART report and it seemed to pass.

 

I'm still new to unRAID and not really sure how to interpret the logs and SMART reports. I'm wondering if my drive is OK or if it is failing. It is quite old so wouldn't be surprised if failing, but how should I proceed? I have enough space on the server to copy the data from the drive in question to other drives and then start up the array and rebuild parity without this drive. I could then do a preclear on the drive to test it. Does this sound like a good procedure?

 

I've also attached the SMART report for the drive in question from after I swapped the SATA cable and switched the SATA port.

 

tower-diagnostics-20170116-0921-anon.zip

tower-smart-20170124-1859.zip

SMART for disk looks OK.

 

You need to rebuild the drive, not rebuild parity. That is the whole point of unRAID, you can rebuild the disk.

 

The red X means unRAID has disabled the disk due to a write failure. After a write fails and unRAID disables it, unRAID will not use the disk again until it is rebuilt. This is because the data on the disk is no longer valid. unRAID is now emulating the disk using all other disks plus parity to calculate the data for the disk. The failed write was emulated, any subsequent writes to the disk were emulated, any reads from the disk are emulated. The valid data is in the parity array waiting for you to rebuild it.

 

Since the disk looks OK you can rebuild to the same disk.

 

What do I do if I get a red X next to a hard disk?

 

Thanks for the help. What should I be looking for in the diag log and in the smart report that would have indicated that the drive was bad and should be replaced?

 

I'm going through rebuilding the drive now. Is there anything I can do once it is rebuilt to test it and make sure it is OK?

Look in Settings - Disk Settings - Global SMART Settings. That shows you the SMART attributes that are normally monitored because they indicate problems with the disk. Known ATA S.M.A.R.T. attributes

 

To test, go to Main - Array Devices and click on the disk to get to its page, then under Self-Test, you can run an extended SMART test.