I am using a Raspberry Pi 4 (4GB RAM) with 2 HDHomerun quad tuners and a USB connected WD Duo 8TB raid 1 (2 4TB hard disks). I am running version 2022.02.09.0020 of Unix DVR server that runs on the USB hard disks and has a R/O main filesystem. I am running headless. I have added no software. It seems that with this version I am going from 95% memory to less than 75% memory in about a week. It normally stays in the 95-90% range. I do not connect to Channels DVR from outside my home network. I do sometimes SSH to the Raspberry Pi 4. I can post the Channels DVR web page if needed. Everything seems to be running correctly. Not sure what to do. I am a retired Computer Programmer with over 30 years of experience.
I use the Pi Image as provided by Channels, and have never seen it drop below 94% free on either of my Pi's.
OS: 2022.0131.0323
Server: 2022.02.26.2221
I just updated to current server: 2022.03.03.0017
If you use a pi, i highly recommend their image and nothing else.
The memory stats are bogus, I wouldn't worry about them.
Enjoy your setup and watch tv.
except buff/cache memory is just as good as available and will be freed as soon as any app requires it.
Recommended reading - The /proc Filesystem — The Linux Kernel documentation
MemAvailable
An estimate of how much memory is available for starting new applications, without swapping. Calculated from MemFree, SReclaimable, the size of the file LRU lists, and the low watermarks in each zone. The estimate takes into account that the system needs some page cache to function well, and that not all reclaimable slab will be reclaimable, due to items being in use. The impact of those factors will vary from system to system.