diff options
| -rw-r--r-- | doc/manual/nix-collect-garbage.xml | 10 | ||||
| -rw-r--r-- | doc/manual/nix-store.xml | 80 |
2 files changed, 50 insertions, 40 deletions
diff --git a/doc/manual/nix-collect-garbage.xml b/doc/manual/nix-collect-garbage.xml index 1de50408e..dc84cd803 100644 --- a/doc/manual/nix-collect-garbage.xml +++ b/doc/manual/nix-collect-garbage.xml @@ -57,16 +57,6 @@ </listitem> </varlistentry> - <varlistentry> - <term><option>--min-age</option> <replaceable>age</replaceable></term> - <listitem> - <para> - This option corresponds to the <option>--min-age</option> - option in <command>nix-store <option>--gc</option></command>. - </para> - </listitem> - </varlistentry> - </variablelist> </refsection> diff --git a/doc/manual/nix-store.xml b/doc/manual/nix-store.xml index 82c55daba..da96630a5 100644 --- a/doc/manual/nix-store.xml +++ b/doc/manual/nix-store.xml @@ -167,24 +167,37 @@ output.</para> <title>Description</title> <para> - The operation <option>--gc</option> performs a garbage - collection on the Nix store. What it does specifically is - determined by the sub-operation, which is one of the - following: + Without additional flags, the operation <option>--gc</option> + 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 <quote>roots</quote>, are deleted. + </para> + + <para> + The following flags may be specified: </para> <variablelist> <varlistentry> + <term><option>--print-roots</option></term> + <listitem> + <para> + This operation prints on standard output the set of + roots used by the garbage collector. + </para> + </listitem> + </varlistentry> + + <varlistentry> <term><option>--print-live</option></term> <listitem> <para> This operation prints on standard output the set of <quote>live</quote> store paths, which are all the store - paths reachable from a set of <quote>root</quote> store - expressions read from standard input. Live paths should - never be deleted, since that would break consistency — - it would become possible that applications are installed + 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. </para> @@ -215,32 +228,39 @@ output.</para> </variablelist> - <para> - The set of root store expressions is read from standard input. - Each line should contain exactly one store path. - </para> + </refsection> + + <refsection> + <title>Roots</title> + + <para>The roots of the garbage collector are all store paths to + which there are symlinks in the + directory <filename><replaceable>prefix</replaceable>/nix/var/nix/gcroots</filename>. + For instance, the following command makes the + path <filename>/nix/store/d718ef...-foo</filename> a root of + the collector: + +<screen> +$ ln -s /nix/store/d718ef...-foo /nix/var/nix/gcroots/bar</screen> + + That is, after this command, the garbage collector will not + remove <filename>/nix/store/d718ef...-foo</filename> or any of + its dependencies.</para> + + <para>Subdirectories + of <filename><replaceable>prefix</replaceable>/nix/var/nix/gcroots</filename> + are also searched for symlinks. Symlinks to non-store paths are + followed and searched for roots, but TODO.</para> - <para> - The option <option>--min-age</option> specifies a minimum time - in hours that an unreachable store path must not have been - used before it is considered dead. The default is 0 (consider - all unreachable store paths dead). Whether a store path has - been used is determined by looking at its access time - (<literal>atime</literal>), so this does not work if the store - is located on a file system that has the - <literal>noatime</literal> option set. - </para> + </refsection> + + <refsection> + <title>Configuration file</title> - <warning> - <para> - You generally will want to use the command - <command>nix-collect-garbage</command>, which figures out - the roots and then calls this command automatically. - </para> - </warning> + <para>TODO</para> </refsection> - + </refsection> |