Had an issue last week with my array. One of the hard drives had a few write errors and therefore got taken out of the array by unRaid.

 

I had a look at the Smart reports and everything seemed ok, checked the cables which also seemed to be in place. I tried to readd the drive to the array but unRaid threw back some more write errors as the drive was being rebuilt.

 

I removed the drive from the array again and replaced it with a spare that I had ready to go.

 

Started a pre-clear on the drive which was giving write errors, it got 11% in on the pre-read and froze. At this point I was getting ready to RMA, but thought I'd give it one last chance at a preclear. This time it went through a pre-clear without problems, results below. I then ran another preclear on the drive but with three cycles, which it also passed - results below.

 

I am now not sure if I should trust this drive or not!

 

One cycle preclear:

http://pastebin.com/raw.php?i=Dg7kSXck

 

Three Cycle Preclear:

http://pastebin.com/raw.php?i=Kxg6SHyd

Drive looks fine from a smart report perspective, but drives can fail without showing signs.

 

There are lots of reasons for drive hangs and general weird behavior than a bad drive. Bad or loose SATA cables, power splitters, controllers that need firmware updates, incompatibilities, bad controller ports, bad drive cages, ...

 

If a drive is acting flakey I suggest changing everything. Put it on a controller with cabling that is working on another drive and see if the drive fails there. It so you know its the drive. If not you've got to use a logical process to narrow down the issue.

Run another SMART short test, it seems the drive has been on for nearly a week longer than when the last SMART test was run (5857 vs 5712).  If that doesn't show any issues, you might want to look into power supply, power cables, or sata cables to make sure everything is connected firmly and within tolerance.

 

The reason this seemed odd to me is because I thought (perhaps wrongly) that preclear invoked SMART short tests as well at the end before getting the SMART report.

 

Power_On_Hours          0x0032  092  092  000    Old_age  Always      -      5857

 

SMART Self-test log structure revision number 1

Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error

# 1  Short offline      Completed without error      00%      5712        -

Three error-free pre-clear cycles and a virtually perfect set of SMART parameters sure look like a good drive.

 

I suspect you simply had a "hiccup" with the drive ... it may not have even been the drive; it could have been a not-quite-secure cable or an electrical "glitch" in the controller.

 

Was the drive connected to the SAME port using the SAME cable as it had been when it gave you the problem in the array?

 

Bottom line:  I don't think there's anything to worry about with that drive, but if it gives you more peace of mind, RMA it.  But I'd keep it ... and RMA it if the problem reoccurs (which I doubt it will).