Why is Raspbian running out of RAM?

Question

DLNA

Good afternoon. I have a raspberry Pi 3, hard drive connected via USB, operating system raspbian.
The main task of the raspberry pi is to stream video from the hard drive over the network to the TV. To do this, a minidlna server has been raised on the raspberry pi, which, in general, does its job.
Problem: when reading and writing movies to this hard drive (and when watching videos on a TV, of course, too), the RAM of the device is completely clogged, and probably for this reason the video starts to interrupt.
Usually free are about 27 MB.
Tell me please, is this normal? Maybe it's the features of ext4? Or will RAM be freed as needed? Or is it a leak?
Thanks in advance.

Answer 1

Feel free to add buffers/cached to free memory - this is also free memory, just temporarily used for the file system cache.
Try a command like free -m
www.linuxatemyram.com