One of my array drives red balled and one of my drives in a two pool cache went off line.  As I suspected, it turned out to be a loose power cable both drives share.  After tightening the cable I rebuilt parity and scrubbed my cache pool which corrected numerous errors.  I noticed my array drive was giving a warning of "failing now"  for the Spin_Retry_Count.  The value hasn't increased since bringing the drive back online and rebuilding parity.  Is my drive really dying or is this just a result of the loose power connection.  I've attached a smart report for the drive in question.  Thanks. 

TOSHIBA_HDWD120_86M6SPMAS-20170509-0801.txt

IF you google this parameter (smart attribute 10), you will find that it is usually considered critical.  It seems to indicate that the drive is having problems coming up to speed. 

 

From the number of hours on it (and if you have had it in an unRAID server), it is probably still in warranty.  If so, just return it under warranty.  (The few times that I have returned a drive under warranty, the new drive has been shipped within 24 hours of receipt so I know they don't look at them at that point.  Plus, the customer is always right and good customer relations start on that  premise.  However, they probably do keep records on returns and if you appear to attempting to 'work' the system, you could be flagged for 'special attention'.)