Like many of you, I was duped into buying WD RED disks when I originally set up my F4-210 NAS. Western Digital marketed WD RED as the pinnacle of NAS storage drives. Since you are reading this post you probably know what is coming.
This is kind of an all around failure. You know how there are drive lights on the front?

Whenever a drive is having trouble the light for it is supposed to turn red, possibly flash. Maybe, just maybe, the whole NAS make some noise? Nada.
Symptoms
Regrettably, I’ve had to do some Windows stuff lately. This resulted in two Windows 11 machines being created in addition to the Windows 10 machine I built a couple of years ago. Thankfully I still have half a dozen Linux machines around the office so it isn’t a completely virus infested place.
Linux machines had no trouble connecting to and using NAS. Windows machines randomly disconnected multiple times per day. Many times I would have to reboot the Windows machine because it would spit up Drive letter already in use errors as it tried to reconnect. Didn’t matter which machine. Both 10 and 11 had the same problem.
Contact Support
I gotta say, technical support for Terramaster has a problem reading email.
I had many exchanges where I explicitly stated in bold the drive randomly disconnected from Windows machines, then reconnected. They continually sent me a link of how to configure the NAS to connect the first time.
When I finally got through to someone who read the email they told me how to run some tests to generate logs. I was then to zip the logs and part them some place like DropBox with a link so they could pull down the logs. I complied.
Almost a week went by and I heard nothing.
Finally I went back into the help chat and the tech I got had the audacity to tell me they never got the logs. I dutifully pasted the link that was two paragraphs down in the exchange. They told me to reply to the email with the zipped file attached (like that never gets stripped by virus checkers and email servers!).
The Posterior Violation of WD Red
These supposedly built for business NAS disks come with a pathetic three year warranty. Hard drives are supposed to have a five year MTBF (Mean Time Between Failure). Imagine my surprise when less than six months past the end of the warranty period I hear this from technical support.
Your HDD2 has a noticeable abnormality and has been removed from the storage pool. The current issue is likely related to this.

In addition, your HDD4 also has I/O errors. Optimistically, it might just be a loose connection, but it’s unclear if there are more serious issues. You can try cleaning off dust.

I bought five drives for this four drive NAS assuming one would go tits up early and I would just swap the drive. There were no warnings, emails, or nasty noises from the NAS. I had it configured for RAID 10 and it unceremoniously dropped a drive from the pool.
Yes, I could have stuck in the spare WD RED 4TB that has been sitting in its box for over three years . . . but . . . a second WD RED was already at death’s door.
Solution
Well, almost a solution.

If memory serves, that is about what I paid for the 4TB drives when I bought them. I didn’t buy a spare. Probably a good thing. I have no idea if the WD RED 4TB spare I have even works. Won’t know until the BOINC machines finish using up all of the other old drives. You know, I have a consumer grade disk from 2006 that is still spinning. Just this past year a Seagate from 2001 went tits up. Being old and knowing hard drives last this long, I’m pretty pissed with WD RED. I’m one guy and there are at most nine machines running at any one time. It’s not like I use the NAS for builds, I just use it to archive things.
First of these drives I stuck in did this
Gotta love DOA drives. Gotta love a five year vs. three year warranty too.
Of course I wanted to be able to stick the replacement drive in whenever it arrives, so now I’m running RAID 5. Supposedly it will automagically add the drive to the pool when I stick it in. Thanks to the holidays, God only knows when the replacement drive will arrive.
Summary
I’m done buying Western Digital. The pathetic quality of WD RED means I’ve bought the last Western Digital products I will ever have.
Why didn’t I buy Seagate the first time?
The bumping.
Every few seconds Seagate drives have to bump their heads because the grease they use is substandard. They are the only brand of spinning disk that bumps drives to avoid sticking yet I get a new drive with a stuck head out of the box. It’s bad enough when it is just one Backup Hub drive sitting on the desk next to you. When it is three drives in a NAS on the other side of the room that have managed to get their bumping in synch . . . Going to be a real joy when I put the fourth drive in!