Oct 5, 2013 | Linux Shell Scripting, Ubuntu 12.04 Server Management
If you don’t have any additional disks, you can create a file somewhere on your filesystem, and use that file for swap space. The following dd command example creates a swap file with the name “swapfile” under /root directory with a size of 1024MB (1GB). # dd if=/dev/zero of=/root/swapfile bs=1M count=1024 1024+0 records in 1024+0 records out Change the permission of the swap file, only allow root access. # chmod 600 /root/swapfile Using mkswap command make this file as a swap file. # mkswap /root/swapfile Setting up swapspace version 1, size = 1048572 KiB no label, UUID=########-####-####-####-############ Enable the newly created swapfile. # swapon /root/swapfile Using your favourite text editor, append the following line to the /etc/fstab file, to make this swap file available as a swap area even after a reboot. # nano /etc/fstab /root/swapfile swap swap defaults 0 0 Verify the newly created swap area. # swapon -s Filename Type Size Used Priority /dev/xvdb partition 524284 0 -1 /root/swapfile file 1048572 0 -2 To verify whether the system takes all the swap space mentioned in the /etc/fstab without rebooting, you can do the following, which will disable and enable all the swap partition mentioned in the /etc/fstab #swapoff -a #swapon -a #swapon -s Filename Type Size Used Priority /dev/xvdb partition 524284 0 -1 /root/swapfile file 1048572 0...
