How to clear system page and buffer cache daily on linux server ?
In this article, we will see how to clear the system page and buffer cache daily on our linux system.
So the idea is to create a script and put it in our cron daily schedule location.
Lets see what we need to do step-wise.
1. Create the new script file in cron.daily.
[root@ngelinux001 ~]# cd /etc/cron.daily/ [root@ngelinux001 cron.daily]# ls -ltr total 24 -rwxr-xr-x. 1 root root 2239 May 22 2015 certwatch -rwxr-xr-x. 1 root root 618 May 22 2015 man-db.cron -rwxr-xr-x. 1 root root 744 Aug 16 2016 snapper -rwx------. 1 root root 219 Sep 25 2017 logrotate -rwx------. 1 root root 208 Nov 9 2017 mlocate -rwxr-xr-x. 1 root root 434 Nov 27 2017 0logwatch [root@ngelinux001 cron.daily]# touch clearcache [root@ngelinux001 cron.daily]# chmod 755 clearcache [root@ngelinux001 cron.daily]#
2. Now edit the file and put these contents.
#!/bin/bash echo 3 > /proc/sys/vm/drop_caches
3. Now check buffer cache usage and run the script.
[root@ngelinux001 cron.daily]# free -g
total used free shared buff/cache available
Mem: 255 6 122 0 126 210
Swap: 15 0 15
[root@ngelinux001 cron.daily]# ./clearcache
[root@ngelinux001 cron.daily]# free -g
total used free shared buff/cache available
Mem: 255 6 244 0 3 228
Swap: 15 0 15
[root@ngelinux001 cron.daily]#
As we can see the memory is now free from the buffer.
Now this script gets scheduled daily to run alongwith cron.
Just make sure the cron service is running fine.
[root@ngelinux001 cron.daily]# service crond status Redirecting to /bin/systemctl status crond.service ● crond.service - Command Scheduler Loaded: loaded (/usr/lib/systemd/system/crond.service; enabled; vendor preset: enabled) Active: active (running) since Fri 2022-06-10 13:43:14 EDT; 4 days ago Main PID: 2769 (crond)