Disabling VirtualMemory does not free up disk space

[Adek336]

hrev33753 gcc4+2 hybrid

Disable VirtualMemory, reboot, disk space still used by swap. Go to VirtualMemory preferences ; note that the size slider is not disabled. Anyhow, moving the slider to 1 MiB does not free up memory either. /boot/var/swap is still 2 GiB.

Removing the file frees up memory and doesn't introduce any problems or crashes.

[leavengood]

Taking ownership.

[leavengood]

A user in IRC found this bug as well, but in his case deleting the file did not seem to actually free the disk space. Either way the system should remove or at least truncate to 0 the swap file when virtual memory is disabled.

I'll attempt to make the fix which does one or the other. It will be my first kernel change ;)

[hamish]

The way you fix this is relevant to a patch I'm working on in #3723.

With support for swap on different volumes, simply deleting /var/swap at boot won't work. Also, deleting the swap file from the volume specified in the config won't work either, because the user could have changed the swap volume and rebooted, leaving a dormant swap file on the old volume.

I thought a possible solution might be to symlink /var/swap to wherever the swap file actually is, and delete through that at boot. This would require that the target volume be manually mounted and then unmounted for the deletion.

Ideally, there would be a procedure to switch off virtual mem at system shutdown which would make use of the existing swap_file_delete() function.

[kallisti5]

#8971 opened to track the issue with the non-erased swap.

After the OS releases the swap, the file can be erased. (however, remember to empty the trash to regain the space!)

[waddlesplash]

Fixed in hrev58195. There are still issues with resizing or disabling at runtime, but at least the space will be released after a reboot now. The remaining issues are tracked in #7550 and #8971.