Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have two Linux boxes, one of which doesn't have much RAM or disk space. How would I go about setting up a swap file on the second machine for the first to use?

share|improve this question
I do suspect an off board swap file is going to be really slow. – Journeyman Geek Sep 29 '12 at 12:21
@JourneymanGeek: Not necessarily... ordinary Ethernet can sometimes be faster than an old hard disk [or 1.1 USB stick]. (Trivia: Windows 3.11 had built-in support for swap over NetBIOS.) – grawity Sep 29 '12 at 12:37
If you have an option to swap to a pen drive or a SDcard (preferably a SDcard with SLC memory) then this might be much faster. – Hennes Sep 29 '12 at 12:38
up vote 4 down vote accepted

You have lots of choices. You can use NBD a network block device. You can set up an NFS mount and swap over it. You can swap over CIFS.


  1. Mount a network drive.

  2. Create a file on it of the appropriate size. (You can use dd if=/dev/zero of=/path/to/swapfile bs=xxx count=xxx)

  3. Make that file a swap device. (Use mkswap.)

  4. Mount it (Use swapon.)

  5. Configure it for permanent use. (Depends on your distribution. Check /etc/fstab.)

share|improve this answer
Note that swap over NFS was disabled for a long time, although it's working again in kernel 3.6. (The page you linked to, however, has very outdated instructions, including patching a 2.2 kernel...) – grawity Sep 29 '12 at 12:32
one more option - ATAoE :) – Serge Sep 29 '12 at 12:33
Unfortunately, the OP didn't specify hardware/software. It works on the Raspberry Pi and modern desktops. I believe swap over CIFS works on OpenWRT and most router firmwares. – David Schwartz Sep 29 '12 at 12:33
hmm, or maybe iscsi swap – Journeyman Geek Sep 29 '12 at 12:37

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.