hly0001,
First a caveat ...
I've no experience with WD Red Plus drives, although I expect to receive four of them at the end of this month. Others in this forum are probably experts on your specific disk and probably know THAT noise. So, hopefully someone else will reply and share their story.
In a nutshell, ... yes it sounds weird ... as in NOT normal. It sounds impaired.
If the cause can not be determined within 30 minutes, then I strongly encourage you to immediately return the drive to vendor.
Now, having said that, I do have experience with other Personal Computer drives, and several years in storage engineering (larger disks & tape drives) as project manager for several disks in the early 1990s. Those were 9", 5", and 3.5" attached to DEC VAXs and Alphas. Based on personal and professional experience ... your disk noise sounds a bit like the mechanical arm (that moves the read/write head) is launching from its 'parked' position ... then possibly retracting back onto the 'parking' ramp. This is merely a guess ...as the video sound is not super clear. As I listened, I noted 3 sounds, a time delay, then ONLY 2 sounds. Typical failure modes would be cyclic ... with exactly the same number and duration of sounds. To me, the later set of sounds were not identical to the first; they were not cyclic. Very odd. Maybe the heads are stuck to the platter surface and consequently we hear the platter motor ... 'grunt' ... a low guttural noise ... sometimes heard when an electrical motor is blocked (or locked) from rotation.
Once again, only a guess ...without more intimate knowledge of that specific drive design or experience with its failure modes. Also, the internal physical design of the Western Digital Red Plus ... might be something I've never seen. I've seen the internals of the big and little drives, so I'm not curious anymore to ... 'crack em open'.
If not cycling back and forth ...( off and then onto the parking ramp ) ... it could be some firmware diagnostic (built in self tests) issuing positioning commands. Once again, guessing. The drive could even be receiving some external commands.
I see the graph indicates reads and writes occurring. Also, I see it was for exactly 1 minute. Did you activate this read/write action OR
merely monitor the activity initiated by unknown source? Tell me more about the graph and software that created it.
Another thought ... some drives used to have a dedicated 'servo' head ... which maintained a finely synchronized rotation ( a phase locked loop PLL).
Other designs ... embedded a servo track between the data sectors... so each data head read servo pulses, then read or wrote data, the again sensed servo pulses as the platters rotated. This is how they stayed on center of cylinder track.
Suggestions:
(1) unplug command cable ... of course leave power cable attached. (;<)) Does drive still make noise?
(2) Confirm no operating system software is issuing commands. Look in system activity monitor available on your OS of choice.
That is all for now.
Got to sleep.
olddog9