Noticed that since this morning I have a yellow alert in my log:
Fri Jan 17 2014 10:11:23 Volume: Volume 'data' health changed from 'REDUNDANT' to 'DEGRADED'.
Somehow, there is no additional warning or error.
On the System/ Volumes view, I see one of the three WD 4 TB drives not in blue but in black. Disk State is somehow still online. The light is solid blue.
Apparently, the 3rd drive is not any longer part of the RAID 5, but the NAS is not alerting a drive failure.
Updating your backup is the first order of business.
It is probably best to contact support on the array.
I guess you could try removing/reinserting the drive with the NAS running and see if it gets re-added/rebuilt. Or take the opportunity to upgrade to 6.1.6 beta, and do the factory reset.
EDIT: You should probably also download the logs and look at the SMART stats for the drive. Maybe also run lifeguard on an PC to check it.
Backup is in progress. Looking at the disk_info.log is quite irritating, as it does only shows two drives (sda and sdb), while three are in the NAS.
Once the backup is done, I will try to remove/ reinsert the drive again and see what's happening. A spare drive is as well on its way, so let's keep fingers crossed.
