36b059748d
Documentation on "classic" commands with many sub-commands are notoriously hard to discover due to lack of overview and anchor links. Additionally the information on common options and environment variables is not accessible offline in man pages, and therefore often overlooked by readers. With this change, each sub-command of nix-store and nix-env gets its own page in the manual (listed in the table of contents), and each own man page. Also, man pages for each subcommand now (again) list common options and environment variables. While this makes each page quite long and some common parameters don't apply, this should still make it easier to navigate as that additional information was not accessible on the command line at all. It is now possible to run 'nix-store --<subcommand> --help` to display help pages for the given subcommand. Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2.2 KiB
Name
nix-store --gc - run garbage collection
Synopsis
nix-store --gc [--print-roots | --print-live | --print-dead] [--max-freed bytes]
Description
Without additional flags, the operation --gc performs a garbage
collection on the Nix store. That is, all paths in the Nix store not
reachable via file system references from a set of “roots”, are deleted.
The following suboperations may be specified:
-
--print-roots
This operation prints on standard output the set of roots used by the garbage collector. -
--print-live
This operation prints on standard output the set of “live” store paths, which are all the store paths reachable from the roots. Live paths should never be deleted, since that would break consistency — it would become possible that applications are installed that reference things that are no longer present in the store. -
--print-dead
This operation prints out on standard output the set of “dead” store paths, which is just the opposite of the set of live paths: any path in the store that is not live (with respect to the roots) is dead.
By default, all unreachable paths are deleted. The following options control what gets deleted and in what order:
--max-freedbytes
Keep deleting paths until at least bytes bytes have been deleted, then stop. The argument bytes can be followed by the multiplicative suffixK,M,GorT, denoting KiB, MiB, GiB or TiB units.
The behaviour of the collector is also influenced by the
keep-outputs and keep-derivations settings in the Nix
configuration file.
By default, the collector prints the total number of freed bytes when it
finishes (or when it is interrupted). With --print-dead, it prints the
number of bytes that would be freed.
{{#include ./opt-common.md}}
{{#include ../opt-common.md}}
{{#include ../env-common.md}}
Examples
To delete all unreachable paths, just do:
$ nix-store --gc
deleting `/nix/store/kq82idx6g0nyzsp2s14gfsc38npai7lf-cairo-1.0.4.tar.gz.drv'
...
8825586 bytes freed (8.42 MiB)
To delete at least 100 MiBs of unreachable paths:
$ nix-store --gc --max-freed $((100 * 1024 * 1024))