Swap Usage - 年糕

Add Virtual Memory#

Get file blocks (The number of swap partitions depends on your physical memory and disk usage, usually 1-2 times the size of physical memory)

dd if=/dev/zero of=/var/swapfile bs=1M count=2048

# The block_size and number_of_block can be customized, for example, bs=1M count=1024 represents setting a 1GB swap partition.

Create swap file
```
/sbin/mkswap -f /var/swapfile
```
Give 600 permission to swapfile
```
chmod 600 /var/swapfile
```
Activate swap file
```
/sbin/swapon /var/swapfile
```
Check if swap is correct
```
/sbin/swapon -s
```
Add to fstab file for automatic startup during system boot (to prevent swap partition from becoming 0 after restart)
```
vi /etc/fstab
// Add at the end
/var/swapfile swap swap defaults 0 0
```
Reboot the system
```
reboot
```
Check the status of swap partitions
```
free -m
```

Remove Virtual Memory#

Stop the swap partition
```
/sbin/swapoff /var/swapfile
```
Delete the swap partition file
```
rm -rf /var/swapfile
```

Delete the automatic mount configuration command

vi /etc/fstab
// Delete the following content
/var/swapfile swap swap defaults 0 0