Swappiness

get current setting

get

sysctl kernel.ostype

$ sysctl -a

$ sysctl -a | grep kernel

$ sysctl -a | more

ie swappiness

https://www.howtogeek.com/449691/what-is-swapiness-on-linux-and-how-to-change-it/

cat /proc/sys/vm/swappiness

sudo sysctl vm.swappiness=0

or

sudo sh -c ‘echo 0 > /proc/sys/vm/swappiness’

persistent

old

/etc/sysctl.conf

# backup

sudo cp -p /etc/sysctl.conf /etc/sysctl.conf.`date +%Y%m%d-%H:%M`

sudo sh -c 'echo "" >> /etc/sysctl.conf'

#or

sudo vi /etc/sysctl.conf

   # add `vm.swappiness = 0`

## apply configu

sysctl -p

automatiquement

sudo sh -c 'echo "" >> /etc/sysctl.conf'

sudo sh -c 'echo "#Set swappiness to 0 to avoid swapping `date +%Y%m%d-%H:%M`" >> /etc/sysctl.conf'

sudo sh -c 'echo "vm.swappiness = 0" >> /etc/sysctl.conf'

new (.d)

sysctl how to configure

https://www.cyberciti.biz/faq/reload-sysctl-conf-on-linux-using- sysctl/

/etc/sysctl.d/

cat /etc/sysctl.d/99-swappiness.conf

vm.swappiness=10

How to reload sysctl.conf variables on Linux

Type the following command to reload settings from config files without rebooting the box:

sysctl --system

The settings are read from all of the following system configuration files:

/run/sysctl.d/*.conf

/etc/sysctl.d/*.conf

/usr/local/lib/sysctl.d/*.conf

/usr/lib/sysctl.d/*.conf

/lib/sysctl.d/*.conf

/etc/sysctl.conf

note

/etc/sysctl.conf

vm.swappiness = 1

vm.dirty_background_ratio = 3

vm.dirty_ratio = 80

vm.dirty_expire_centisecs = 500

vm.dirty_writeback_centisecs = 100

kernel.shmmax = 4398046511104

kernel.shmall = 1073741824

kernel.shmmni = 4096

sysctl -p

sysctl -p /etc/sysctl.d/99-swappiness.conf

32 bits = 32768 2^16

64 bits = 4194304 2^22

max pid

bash fork cannot allocate memory

temporary

cat /proc/sys/kernel/pid_max

echo 32768 > /proc/sys/kernel/pid_max

permanent

/etc/sysctl.conf or /etc/sysctl.d/98-pid_max.conf

kernel.pid_max = 4194304