# create swap file
dd if=/dev/zero of=/.swap bs=1048576 count=4096
# format swap
mkswap /.swap
# start swap
swapon /.swap
# check
free -h
# onboot
echo "/.swap swap swap defaults 0 0" >> /etc/fstab
原文：https://www.cnblogs.com/sangria/p/14652441.html