Why is Linux using all my memory?

The reason Linux uses so much memory for disk cache is because the RAM is wasted if it isn’t used. Keeping the cache means that if something needs the same data again, there’s a good chance it will still be in the cache in memory.

How do I see what is using my memory Linux?

cat Command to Show Linux Memory Information

Entering cat /proc/meminfo in your terminal opens the /proc/meminfo file. This is a virtual file that reports the amount of available and used memory.