I have the EX2 Ultra for about three years. Last night I notice that disk 1 has a red error on it so I pull it out then put it back in, the control panel says it is rebuilding it, now it is green. But now I see it is RAID 1, both disks are green but I dont know if it is really RAID or not. If I try to select RAID 1 it says it will format both disks which will delete all my data. Im confused. I dont even know if Disk 1 is good anymore.
Disk1 was probably the primary disk of a RAID1. The red led indicates an error on this disk which was not recoverable. By pulling that disk out, disk2 became probably the primary disk and restored the content of disk1 without detecting an error.
Reinitializing a RAID1 as a RAID1 will surely make all data inaccessible by normal means.
Because both drives are about three years old and probably have been in RAID1 all the time, that error on disk1 is a severe sign, that at least drive1 will fail in total soon: replace it asap.
If you have bad luck, drive2 may fail soon too, because both drives were used with the same intensity over three years. For this you hopefully have follwed the rule of thumb to have nearly always at least two verified backups ready for restoring your data.
You’ll also get a red light if the disk is good but more than ~90% full.
(post deleted by author)