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-freed bytes

          Keep deleting paths until at least bytes bytes have been deleted, then stop. The argument bytes can be
          followed by the multiplicative suffix K, M, G or T, 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))

                                                                                               nix-store --gc(1)