Difference between revisions of "Swap"
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(Created page with "== Swap == Swap usage can lead to performance degradation of your server. So we highly recommend to disable swap space and increase the memory. How to disable swap space: ...") |
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Swap usage can lead to performance degradation of your server. So we highly recommend to disable swap space and increase the memory. | Swap usage can lead to performance degradation of your server. So we highly recommend to disable swap space and increase the memory. | ||
| − | How to disable | + | ===How to disable=== |
root@vmsniff:~# swapoff -a | root@vmsniff:~# swapoff -a | ||
| Line 16: | Line 16: | ||
# swap was on /dev/sdb2 during installation | # swap was on /dev/sdb2 during installation | ||
#UUID=4cf42564-4339-42ed-b7ec-29644a3085f1 none swap sw 0 0 | #UUID=4cf42564-4339-42ed-b7ec-29644a3085f1 none swap sw 0 0 | ||
| + | |||
| + | |||
| + | ===How to configure=== | ||
| + | Most distributions have set by default to use swap when Ram usage exceeds 40% | ||
| + | check your swappiness values with | ||
| + | cat /pro/sys/vm/swappiness | ||
| + | |||
| + | You can change it in a run-time (after restart default swap settings will beback) , effect is instant | ||
| + | echo '0' > /pro/sys/vm/swappiness | ||
| + | |||
| + | |||
| + | You can set the value permanent adding line at end of /etc/sysctl.conf | ||
| + | vm.swappiness=0 | ||
| + | |||
| + | (The settings means to use swap only when there is no Ram free for latest kernels) | ||
| + | |||
| + | ===Make swap empty=== | ||
| + | swapoff -a | ||
| + | swapon -a | ||
Revision as of 11:20, 7 May 2020
Swap
Swap usage can lead to performance degradation of your server. So we highly recommend to disable swap space and increase the memory.
How to disable
root@vmsniff:~# swapoff -a
Then edit the /etc/fstab file and comment out the swap lines. E.g.
proc /proc proc defaults 0 0 # / was on /dev/md0 during installation UUID=17e56a9a-0f42-44ca-90e8-570315708def / xfs relatime 0 1 # swap was on /dev/sda2 during installation #UUID=0a403f5e-0505-4055-a219-70217b6b74d1 none swap sw 0 0 # swap was on /dev/sdb2 during installation #UUID=4cf42564-4339-42ed-b7ec-29644a3085f1 none swap sw 0 0
How to configure
Most distributions have set by default to use swap when Ram usage exceeds 40% check your swappiness values with
cat /pro/sys/vm/swappiness
You can change it in a run-time (after restart default swap settings will beback) , effect is instant
echo '0' > /pro/sys/vm/swappiness
You can set the value permanent adding line at end of /etc/sysctl.conf
vm.swappiness=0
(The settings means to use swap only when there is no Ram free for latest kernels)
Make swap empty
swapoff -a swapon -a