This is just a difference in terminology. Why does top and free say all my ram is used if it isn't? If, however, you find yourself needing to clear some RAM quickly to workaround another issue, like a VM misbehaving, you can force linux to nondestructively drop caches using echo 3 | sudo tee /proc/sys/vm/drop_caches. The only reason anyone ever wants to disable disk caching is because they think it takes memory away from their applications, which it doesn't! Disk cache makes applications load faster and run smoother, but it NEVER EVER takes memory away from them! Therefore, there's absolutely no reason to disable it! If applications want more memory, they just take it back from the disk cache. No, disk caching only borrows the ram that applications don't currently want.

Disk cache can always be given back to applications immediately! You are not low on ram! Do I need more swap? If your applications want more memory, they just take back a chunk that the disk cache borrowed. It does not take memory away from applications in any way, ever! What if I want to run more applications? This makes it look like you are low on memory, but you are not! Everything is fine! Why is it doing this?ĭisk caching makes the system much faster and more responsive! There are no downsides, except for confusing newbies. Linux is borrowing unused memory for disk caching.

Linux memory usage