1.生成swapfile文件

sudo fallocate -l 4G /var/swapfile
sudo chmod 600 /var/swapfile
sudo mkswap /var/swapfile
sudo swapon /var/swapfile

2.设置为自动启用swapfile

sudo bash -c 'echo "/var/swapfile swap swap defaults 0 0" >> /etc/fstab'