How To Clear Cache and Swap Memory In Linux Ubuntu

How to check cache memory in Linux. Here are the commands to clear cache in Linux Ubuntu or clear memory in Linux.

On Linux, clear cache without root using the following commands or clear swap memory in Linux.

You must understand that a buffer is an area of memory used to temporarily store data while being moved from one place to another. Whereas, a cache is a temporary storage area to store frequently accessed data for rapid access.

The cache in Linux is called Page Cache and the Linux cache approach is called a write-back cache.

See Buffer and Cache Memory Details in Linux

To analyze the amount of system memory and the memory allocated to buffer and cache of the said system, use the free command:

free -m

Clear Memory In Linux

To clear pagecache only:

sync; echo 1 > /proc/sys/vm/drop_caches

To clear dentries and inodes:

sync; echo 2 > /proc/sys/vm/drop_caches

To clear pagecache, dentries and inodes:

sync; echo 3 > /proc/sys/vm/drop_caches

You can also use the following chain of commands to empty buffer and cache:

free && sync && echo 3 > /proc/sys/vm/drop_caches && free

NOTE:

use echo 1 to free page cache:
use echo 2 to free dentries and inodes:
use echo 3 to free page cache, dentries, and inodes:

Clear RAM In Linux

sudo sync; echo 3 > /proc/sys/vm/drop_caches

sudo apt-get clean
sudo apt-get autoclean
sudo apt-get autoremove

Clear Swap Memory In Linux

swapoff -a && swapon -a

That’s all for now.

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