bug#52919: Hidden "disk-image-rw" files aren't deleted after use, filling $tmpdir

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

Mathieu Othacehe <othacehe@gnu.org> skribis:

>> This is new. I think the issue was introduced with recent work on (gnu
>> system image), perhaps from this commit:
>>
>> https://git.savannah.gnu.org/cgit/guix.git/commit/?id=da924796744bbb7b035a986fe5d28d8d613ff6af
>
> Before that commit "guix system vm" was always producing volatile
> images, regardless of the "--volatile" argument. The new behaviour is to
> only produce volatile images if "--volatile" is passed.

I had overlooked the change of default.

> This means that by default, "disk-image-rw" are created in /tmp so that
> QEMU can operate on RW images. The side effect is that those big images
> can fill /tmp pretty quickly as you noticed.
>
> We could use the ~/.cache/guix directory instead to store those
> images. We could also make "--volatile" the default and introduce a
> "--persistent" argument instead. That would restore the previous "guix
> system vm" behaviour.

Yes, reverting to the old behavior for ‘guix system vm’ and adding
‘--persistent’ sounds like a nice option to me.

As for the image backing storage, using ~/.cache/guix/images (with non
dot-prefixed file names) sounds cleaner and safer to me (no risk of /tmp
race or whatever).

Thanks,
Ludo’.