Mem usage question

running rockstor with jellyfin docker, every so often the smb service crashes with OOM error. I have repeatedly checked the mem usage, it always shs around 1.4gb used 2.6gb buff/cache and the swap file (2gb) is usually around 80% usage. I didnt concern myself with this because my understanding of linux is the idea that unused ram is wasted ram, I figured the cache section of the ram was unimportant. is this incorrect?

So all memory is used and swap file almost full? Easy to need some extra memory and OOM. Linux uses all the memory as fs cache so all memory is used, you can check available amount from /proc/meminfo.

it shouldnt be running out of mem.

less than a gb is used by the system and all that yellow area is cache, so I dont understand why the swap usage is so high, and why its throwing oom errors.

You need more memory, either swap or hardware. You’d need memory statistics from the point of OOM so you’d know which process is taking the memory and how much of it.