Ubuntu 增加swap空间大小

1. create a 1G file for the swap.

　　sudo fallocate -l 1G /swapfile

　　we can verify that the correct amount of space was reserved by typing:

　　ls -lh /swapfile

2. Enabling the Swap File.

　　1.Make the file only accessible by typing:

　　　　sudo chmod 600 /swapfile.

2.Make the file as swap space by typing:

　　　　sudo mkswap /swapfile

　　3.Enabling the swap file and allow our system to start utilizing it .

　　　　sudo swapon /swapfile.

　　4.Now you can find that the swap space was added by typing:

　　　　free -h / (sudo swapon --show)

3. Delete the Swap File.

　　1.Disabling the swap file

　　　　sudo swapoff /swapfile

　　2.Remove the swap file

　　　　sudo rm -rf  /swapfile