linux swap ubuntu 添加虚拟内存
Start by creating a file which will be used for swap:
sudo fallocate -l 1G /swapfile
If fallocate is not installed or you get an error message saying fallocate failed: Operation not supported then use the following command to create the swap file:
sudo dd if=/dev/zero of=/swapfile bs=1024 count=1048576
Only the root user should be able to write and read the swap file. Set the correct permissions by typing:
sudo chmod 600 /swapfile
Use the mkswap utility to set up a Linux swap area on the file:
sudo mkswap /swapfile
Activate the swap file using the following command:
sudo swapon /swapfile
To make the change permanent open the /etc/fstab file:
sudo nano /etc/fstab
and paste the following line:
/etc/fstab
/swapfile swap swap defaults 0 0
Verify that the swap is active by using either the swapon or the free command , as shown below:
sudo swapon --show
