Well almost a year and this is the first issue so I think I'm doing good.  Earlier this evening I got the red X next to data drive 5 (it's a 3TB drive).  I'm running V6 of unRaid btw.  Things are working as they should regarding parity because the data (movies) on that drive are still viewable on Plex.  I luckily have a 3TB drive that I was able to use as a replacement.  I realize that I may have skipped a step and could have re-enabled the drive but I panicked.  Anyway, took the array off line, powered down, removed the not working 3TB drive, replaced with a freshly formatted 3TB drive and powered back up.  I can't assign the new disk though.  It doesn't show up.  I am going to check my cables and things to make sure nothing is going wrong there.  Anything else I should check???  Can I install the disk to a new drive slot and rebuild it there?  Thanks all.

Don't you hate those people who reply to their own threads.  I "thought" I remembered that I had read you could infact use any slot and assign so I moved the disk to a new location and it shows up to be assigned now.  But I still need to know what to check to see why the other slot may be uncooperative.  Listen, I know enough to be dangerous so be kind

 

Thanks again.

If it works in one slot but not the other then it must be the cables/backplane/controller port associated with the faulty slot.

 

...replaced with a freshly formatted 3TB drive...

 

What did you mean by this?

 

it's a 3tb drive that had nothing on it.  it was formatted but never used.  I had intended to use it in a bare dock with my video editing system but I figured it would be better served to replace the faulty drive.  So it's possible I guess that nothing was even wrong with the other drive if its a cable or similar issue?

I interpreted "freshly formatted" as a disk that you had somehow formatted as part of the preparation for using it to replace the old disk - that would have been completely unnecessary, of course.

 

It's very likely that the old disk is good. You can test it in another computer, or put it in a spare slot in your server and run some tests on it. Personally, I'd do a long SMART self-test and if it passes I'd pre-clear it and then either add it to the array or keep it as a spare.

 

Your problem is likely to be the SATA cable - they are not very well designed IMO. The plugs are easily knocked partially out of the sockets and the stiffness of the wires doesn't help. It's worth checking the power cable too, especially if you use splitters.