Name

       nix-store --optimise - reduce disk space usage

   Synopsis
       nix-store --optimise

   Description
       The  operation  --optimise reduces Nix store disk space usage by finding identical files in the store and
       hard-linking them to each other. It typically reduces the size of the store  by  something  like  25-35%.
       Only  regular files and symlinks are hard-linked in this manner. Files are considered identical when they
       have the same Nix Archive (NAR) serialisation: that is, regular files must have  the  same  contents  and
       permission (executable or non-executable), and symlinks must have the same contents.

       After  completion,  or  when  the  command is interrupted, a report on the achieved savings is printed on
       standard error.

       Use -vv or -vvv to get some progress indication.

       {{#include ./opt-common.md}}

       {{#include ../opt-common.md}}

       {{#include ../env-common.md}}

   Example
       $ nix-store --optimise
       hashing files in `/nix/store/qhqx7l2f1kmwihc9bnxs7rc159hsxnf3-gcc-4.1.1'
       ...
       541838819 bytes (516.74 MiB) freed by hard-linking 54143 files;
       there are 114486 files with equal contents out of 215894 files in total

                                                                                         nix-store --optimise(1)