dd if=/dev/zero of=/swapfile1 bs=1024 count=524288
mkswap /swapfile1
swapon /swapfile1
vi /etc/fstab
# edit /etc/fstab file, add the following line
/swapfile1 none swap sw 0 0
# save and quit
free -m
swapon -sadd swap file if you only have 1G RAM
原文：https://www.cnblogs.com/otfsenter/p/9626924.html