I would ssh into the machine and run commands like top, lsof and ps to try to figure out what is running and what files are being used.
And iotop in combination with the others
It might be the built in media apps generating thumbnails.
This was my guess. Maybe Plex also processing removal of intros and credits too.
One of the first things I accepted on my DS918+ was, that disks will never be idle. So I packed many services (>20, most docker) on it + a raid1 M2 cache in front of the big raid5 (3x 8TB). access is quite low now and the power to spin the disks 24h per day is not wasted.
DS918+ with 16GB M2-cache and its 4core CPU is a perfect thing to consolidate all those one-thing-solutions. I learned much by doing this. I still enjoy!
Next I will install 2 solar panels on balcony to supply some of the "basis power".
This is a place for all topics regarding Synology hard- and software - especially (but not limited to) their NAS devices.
Just one thing: Let’s please be pleasant to each other and respect that people have different experience levels. Some are pros, some are noobs, yet everybody may have good ideas or interesting questions to ask and comments to make, and all of these shall be heard and appreciated. ❤️
And since we know from TV that all IT nerds 🤓 are h4xx0rs and wear hoodies all the time (if not even ski masks) in front of their computers, I chose an appropriate banner image (image credit).