Swap: Difference between revisions

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=add swap on existing disk=
=add swap on existing disk=
  dd if=/dev/zero of=/swapfile bs=1024 count=1000000.
  dd if=/dev/zero of=swapfile bs=1M count=10000
  mkswap /swapfile.
  mkswap swapfile.
  swapon /swapfile.
  swapon swapfile.

Revision as of 10:55, 13 March 2024

How to handle swappiness

Start top and press O then p to sort by swap.

top -c

Look to see if any swap is being used. si and so is swap in and swap out.

vmstat 1

To return swap to ram.

swapoff -a; swapon -a
(swapoff -a; swapon -a) & watch free -m

See swappiness value.

cat /proc/sys/vm/swappiness

To set swippiness value.

sudo sysctl vm.swappiness=0

sort processes on swap usage.

for PROCESS in /proc/*/; do   swapused=$(awk 'BEGIN { total = 0 } /^Swap:[[:blank:]]*[1-9]/ { total = total + $2 } END { print total }' ${PROCESS}/smaps 2>/dev/null || echo 0);   if [ $swapused -gt 0 ]; then     /bin/echo -e "${swapused}k\t$(cat ${PROCESS}/cmdline)";   fi; done | sort -nr

add swap on existing disk

dd if=/dev/zero of=swapfile bs=1M count=10000
mkswap swapfile.
swapon swapfile.