Hi everyone.
I have a frustrating problem and seem to be the only one with it? Am I?
Purchased 8TB NAS over 8 months ago. In the time I’ve had every drive has come up as degraded or unassigned, some twice.
I clean them, remove and rebuild OK and we’re good to go for about a month. But, it’s just happened twice now in a week. This time I’m giving the HDD a full reformat before inserting for rebuild.
DOES anyone know why this is happening, or have any advice? I’ve had a gutsfull of this product already.
Kind regards, Rob
I can’t offer a solution but can sympathize. I have the 4TB model and in less than one year, I have had to RMA two of the drives and just today got a message that one of the drives is “missing”. Luckily I have not lost any data due to these drive failures but all three incidents have occured within the last 3 months. I guess hte nice thing is that when I RMA the drives, I have been getting a 16 or 32MB cache drive instead of hte 8MB drives that it shipped with. Might see a performance boost if I end up replacing all of them over time. 
I think it’s important to note that a degraded raid 1 volume basically means that the data is out of sync, perhaps do to power failure during a write sequence. Regardless of theories, I’ve can echo your experience with my 8TB unit.
