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How can I create a dedicated hard drive to do "swap"on a ubuntu 12.04 LTS?

dwaynekdclarke
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1 Answers1

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You don't have to use a partition or hdd for swap.

Just create a swap file using dd or fallocate.

Create a file of filled with zeros 1GB in this case:

 dd if=/dev/zero of=/mnt/swap.img bs=1M count=1024

Preferred method: use fallocate instead of dd

NOTE: fallocate is much faster than dd because it quickly allocates blocks and mark them as uninitialized, no I/O to the blocks.

fallocate -l 1024M /mnt/swap.img

Format the file to create a swap device

mkswap /mnt/swap.img

Adding the swap to the running system:

swapon /mnt/swap.img

Make it permanent, edit /etc/fstab and add the following entry:

/mnt/swap.img  none  swap  sw  0 0

More information: https://help.ubuntu.com/community/SwapFaq

Terry Wang
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  • So @Terrywang, therefore if im creating a 4GB swap this is what is should look like sudo fallocate -l 4096m /mnt/4096MiB.swap sudo chmod 600 /mnt/4096MiB.swap sudo dd if=/dev/zero of=/mnt/4096MiB.swap bs=4M count=4096 sudo chmod 600 /mnt/4096MiB.swap sudo mkswap /mnt/4096MiB.swap sudo swapon /mnt/4096MiB.swap gksudo gedit /etc/fstab /mnt/4096MiB.swap none swap sw 0 0 – dwaynekdclarke Aug 01 '13 at 21:14
  • If you use `fallocate` to generate the swapfile, NO you don't need to du it using `dd` again, because they do the same thing, diff is `fallocate` is much faster. Otherwise the steps look good. – Terry Wang Aug 01 '13 at 21:24
  • Well I was successful in creating the swap file, which i most say is running quite well. @terrywang – dwaynekdclarke Aug 02 '13 at 12:43