My Cloud EX4 - Drive Failure or Enclosure Failure

Hello WD Community,

Looking for advice on how to proceed with issue with my EX4. I have very little network experience, mainly software development experience.

I purchased my EX4 in 2014. It has a basic RAID setup, with 4 6TB drives. Bay 2 is RAIDed to bay 1 and bay 4 is RAIDed to bay 3. Everything has been running smooth since I bought it.

Bay 2 started recently flashing a red light and now bays 3 and 4 are flashing red as well. I can not access drives 1 or 3 anymore from my PC or the browser interface. The only information I see is on the NAS display saying that the index is being rebuilt with an estimate of 10’s of millions on minutes. I’ve tried to let it perform the rebuild several times but without success.

Should I start over with a new NAS? New drives? Should I seek the advice of a professional? I don’t know who to reach out to. Network engineer? I don’t know how to troubleshoot this issue and get it resolved. I purchased the EX4 at a Best Buy but they don’t service it.

This is stressing me out and causing sleepless nights!

Any and all advice is appreciated.


Start by assessing the health of each drive by attaching it directly to a SATA port inside your PC:

Are your RAIDs mirrored (RAID 1) or striped (RAID 0)?

Do you need to recover your data?

Thank you for your reply. I appreciate you taking the time to provide me with a path towards a resolution of this issue.

Since I am not a hardware tech and don’t know how to attach my drives to a SATA port, I plan to reach out to a third-party hardware technician to help with the diagnosis of my hard drives and the enclosure.

My drives are RAID (mirrored).

At this point, I don’t know whether I need to have a data recovery service involved. It all depends on the diagnosis of the drives health and the enclosure status. I am hoping it is an enclosure issue and not a drive issue because the data on the drives are the most important thing.

All the best.