Hi.  I just replaced my first ever failed hard drive in my Unity 400 yesterday.  The disk which was replaced was a 6TB 3.5inch NL-SAS 12Gbps in a RAID 6 with seven other drives and then a hot spare.  So the whole thing is nine drives with one as a hot spare.  Presently there is 15TB used in the raid.  Anyway, the drive has been showing that it has been resynchronizing for almost 24 hours.  Is this normal?