Re: Ever-growing store with --gc-keep-outputs?

[Mark H Weaver <mhw@netris.org>]

Hi Pierre,

Pierre Neidhardt <mail@ambrevar.xyz> writes:

>> If, say, “coreutils” is live, then the corresponding “coreutils.drv”
>> will be considered live as well when you pass --gc-keep-derivations.
>
> Is the .drv live forever then?  Even when all the corresponding outputs have
> been deleted from all profiles / generations?

No, certainly not.  To expand on what Ludovic wrote, by passing
--gc-keep-derivations, you are providing an additional way for a .drv to
be reachable from your GC roots.  The .drv file will be kept alive for
as long as any of its outputs are kept alive.  More generally, it will
be kept alive as long as anything that was built upon it is kept alive.
That does not imply that .drv files are kept alive forever.

I've been using --gc-keep-derivations=yes and --gc-keep-outputs=yes for
a long time, and it works well in my preferred mode of operation where I
build everything locally and never use substitutes.  It ensures that
everything needed to build my GC-root-protected store items will be kept
alive.

When I want to free up some disk space, I do the following steps:

(1) update my user profiles and delete old generations
(2) delete older generations in /var/guix/profiles (but always
    keeping the one referenced by /run/booted-system!)
(3) reconfigure the system to remove the old system profiles from
    grub.cfg
(4) guix gc

Does that work for you?

       Mark