Alibaba Cloud host centos virtual memory (swap partition)

1. add a swap file with a size of 2 GB. by default, the of =/swapfile is created in the/var/directory. If I create a file in the/opt/image/directory, change/swapfile in all the operations below to/opt/image/swap # ddif =/dev/zeroof =/swapfilebs = 1 kcount = 2048 1. add a swap file with a size of 2 GB

By default,of=/swapfileThat is, the swapfile file is created under the/var/directory.
If I create a directory in the/opt/image/directory/swapfileAll must be changed/opt/image/swap

# dd if=/dev/zero of=/swapfile bs=1k count=2048000

2. create a SWAP file

# mkswap /swapfile

3. activate the SWAP file

# swapon /swapfile

4. check whether SWAP information is correct.

# swapon -s

5. add it to the fstab file to enable automatic startup during system boot.

Note that the default path of the swapfile file is used, that is,/var/swapfile. If the swapfile file is not in the/var/directory/var/swapfileYou also need to modify it to your own.

# echo "/var/swapfile swap swap defaults 0 0" >> /etc/fstab

6. run the free command to check whether the 2 GB swap partition takes effect.

# free -m

Or, check the meminfo file.

# grep SwapTotal  /proc/meminfo

7. release the SWAP file

# swapoff /swapfile

8. delete the SWAP file

# rm -fr /swapfile