Red drive dropped from RAID due to TLER error - replacement required?

I have a pair of Red drives in RAID 1 via the motherboard southbridge. Over the weekend one of the drives experiened several block access failures, resulting in the RAID going critical and as the drive was kicked out of the RAID, as per the report below:

I’ve pulled the drive out and run Lifeguard on it and no SMART errors are reported, so it appears that TLER timing / reallocation problems caused it to be dropped. I’ve been running a couple of RAIDS with Reds for a couple of years, but this is a first.

Presumably this is grounds for returning the drive, which is only 3 months old, but I’d appreciate confirmation of this.

Hello and welcome to the WD community.

Did you test both drives or just one ? If like you said you have a other RAIDS running normally then i would think one of the drives is having issues or perhaps you can try a different SATA cable, for example to see if this helps. 

Hi ArMak, thanks for your reply.

Do I understand then, that in principle a TLER error would be justifiable grounds for a replacement?

Re your comments, I did only tested the one drive that was flagged as the problem. This particular RAID was upgraded to two 3TB Red drives (replacing a pair of 1TB drives) around 3 months ago. There was never a problem with the previous drives over the time they were in use (about 2 years), so I’d be surprised if the cable was at fault, especially as this new pair of drives had been running OK and undisturbed for 3 months. I’m rather reluctant to reinstall the removed drive again if the TLER is justifiable grounds for a replacement. Is there any TLER-testing software that I can run on this disk while it’s out of RAID (or might I have to wait another 3 months before an error)?

I’ve also been running a separate RAID with another pair of Red 3TB drives for well over a year, with no problems.

A full bad-block-scan (where the whole drive is written and read) should also give a TLER error in case the disk is defective or have some bad blocks.