How can I enable zswap?

Note: Some releases of the kernel aren't capable of using zswap. See bug #1315203.

According to the kernel documentation, zswap can be enabled by setting zswap.enabled=1 at boot time. Zswap is is still an experimental technology,

NOTE: Zswap is a new feature as of v3.11 and interacts heavily with memory reclaim. This interaction has not be fully explored on the large set of potential configurations and workloads that exist. For this reason, zswap is a work in progress and should be considered experimental.

so it would be wise to only enable it temporarily at first:

  1. Hold down Shift at boot to enter GRUB's menu.
  2. Edit the commands for Ubuntu to include zswap.enabled=1 at the end of the linux line.
  3. Press F10 to boot.

If you want to enable zswap permanently, edit the GRUB configuration file to include zswap.enabled=1 at the end of the GRUB_CMDLINE_LINUX_DEFAULT entry.


Kernel 3.13.0-24-generic does not support zswap:

$ cat /boot/config-3.13.0-24-generic | grep ZSWAP
#CONFIG_ZSWAP is not set