4 red solid red light on drives

I have a 3 month old PR4100 NAS with four 4TB drives in RAID 10.

Yesterday, accessing data on the drive became unresponsive - sometimes I could access the data, and the next moment I would be unable. I logged into the NAS control panel and ran a quick system test and the result was a “drive SMART failure”. After running the test all four drive lights turned solid red.

I called WD support and was quickly told that they would replace my whole unit. No troubleshooting. I asked about the data, and they said I’d have to go through a data recovery service first.

The weird part is that ever since that moment where I was having trouble accessing some files, and the drive lights turned red, I’ve been able to fully access the drive - reading and writing. I ran a full current back up of the NAS to a USB drive and all the data seems to be fine. Other than the red lights, the NAS seems fully operational at this time.

The support guy was unable to provide any insight as to what’s happening to this NAS so I thought I’d ask here. Needless to say, this is very disturbing as I bought this 4 bay NAS for the data security only to have the whole unit go belly up in 3 months.


I had a similar issue
I had 1 drive fail in a 4-drive RAID5.
I followed the procedure to replace the drive and everything was looking normal while it was rebuilding the RAID group.
Then there was a power failure before the RAID group finished rebuilding
When it powered back on and rebooted, all 4 drives had their red LED on solid and all 4 drive’s blue LED flickering behind the red.
While the rebuild continued and the red LED were on, the EX4’s dashboard, the shares and all the data was perfectly accessible.
The rebuild completed (according to the dashboard, the RAID5 rebuild was finished and the RAID5 group was OK) and the red LED were still on. But everything was otherwise still normal.
The WD Cust Support had no suggestions and no explanation.
I decided to power cycle and reboot the EX4.
After the reboot, all the red LED were off and everything was back to normal.

But, I would not assume anything.
Always have a 2nd copy (backup) of the entire EX4 (just in case).