How to clear memory cache in Linux

All we need is an easy explanation of the problem, so here it is.


Is there any command that by using I can clean the cache in RHEL?

I used this command:

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

but it didn’t work.

How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

Method 1

Depending on what you want to do you can use 1,2 or 3



Writing to this will cause the kernel to drop clean caches, dentries and
inodes from memory, causing that memory to become free.

To free pagecache:

echo 1 > /proc/sys/vm/drop_caches

To free dentries and inodes:

echo 2 > /proc/sys/vm/drop_caches

To free pagecache, dentries and inodes:

echo 3 > /proc/sys/vm/drop_caches

As this is a non-destructive operation and dirty objects are not freeable, the
user should run ‘sync’ first.

Method 2

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

Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂

All methods was sourced from or, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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