why swapoff -a && swapon -a not help to Decrease the used swap in the linux machine

Asked May 08 '20 at 06:22

Active May 08 '20 at 06:36

Viewed 116 times

on the rhel version 7.5 the used swap is 12G

we change the swappiness from 10 to 1

echo 1 > /proc/sys/vm/swappiness

sysctl -w vm.swappiness=1

echo "vm.swappiness = 1" >> /etc/sysctl.conf

and did the

swapoff -a && swapon -a

then from free -g we still see the same used swap size

so seems that the change to swappiness , and swapoff -a && swapon -a , not help to decease the swap use

the only thing that I think to do is to reboot the linux machine

is it make sense ?

edited May 08 '20 at 06:36

asked May 08 '20 at 06:22

yael

1

What is the reading of free -g after you swapoff -a only, skipping the swapon -a? Does it make the swap size 0? – GMaster May 08 '20 at 06:27
see the update ,,, – yael May 08 '20 at 06:37
After you run swapoff -a only, and if it is successful, the swap will read 0 in all columns. Looks like your OS is having issues turning off swap in the first place. – GMaster May 08 '20 at 06:42
so in that case only reboot can help – yael May 08 '20 at 06:46
Yes, reboot will most likely help – GMaster May 08 '20 at 06:47
Why you need to get swap to zero? It is in most time OK to have something in swap (i.e. all leaked memory from applications like browser and so on). – Lubo May 08 '20 at 07:01
we have hadoop cluster and swap isnt recommended – yael May 08 '20 at 07:17
swapoff is SLLLLOWWWW....turn it off and wait a couples minutes before turning it on. – Rui F Ribeiro May 08 '20 at 07:56

0 Answers0