diff options
Diffstat (limited to 'doc/manual/nix-store.xml')
| -rw-r--r-- | doc/manual/nix-store.xml | 135 |
1 files changed, 133 insertions, 2 deletions
diff --git a/doc/manual/nix-store.xml b/doc/manual/nix-store.xml index da3eae2ec402..db5f8c344622 100644 --- a/doc/manual/nix-store.xml +++ b/doc/manual/nix-store.xml @@ -128,6 +128,7 @@ lrwxrwxrwx 1 ... 2005-03-13 21:10 /home/eelco/bla/result -> /nix/store/1r1134 <arg choice='plain'><option>-r</option></arg> </group> <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg> + <arg><option>--dry-run</option></arg> </cmdsynopsis> </refsection> @@ -166,6 +167,11 @@ the specified store paths. Realisation is a somewhat overloaded term: output. (For non-derivations argument, the argument itself is printed.)</para> +<para>If the <option>--dry-run</option> option is used, then +<command>nix-store</command> will print on standard error a +description of what packages would be built or downloaded, and then +quit.</para> + </refsection> @@ -204,6 +210,10 @@ linkend="sec-nix-build"><command>nix-build</command></link> does.</para> <arg choice='plain'><option>--print-dead</option></arg> <arg choice='plain'><option>--delete</option></arg> </group> + <arg><option>--max-freed</option> <replaceable>bytes</replaceable></arg> + <arg><option>--max-links</option> <replaceable>nrlinks</replaceable></arg> + <arg><option>--max-atime</option> <replaceable>atime</replaceable></arg> + <arg><option>--use-atime</option></arg> </cmdsynopsis> </refsection> @@ -258,7 +268,70 @@ the Nix store not reachable via file system references from a set of </variablelist> -<para>The behaviour of the collector is influenced by the <link +<para>By default, all unreachable paths are deleted. The following +options control what gets deleted and in what order: + +<variablelist> + + <varlistentry><term><option>--max-freed</option> <replaceable>bytes</replaceable></term> + + <listitem><para>Keep deleting paths until at least + <replaceable>bytes</replaceable> bytes have been + deleted, then stop.</para></listitem> + + </varlistentry> + + <varlistentry><term><option>--max-links</option> <replaceable>nrlinks</replaceable></term> + + <listitem><para>Keep deleting paths until the hard link count on + <filename>/nix/store</filename> is less than + <replaceable>nrlinks</replaceable>, then stop. This is useful for + very large Nix stores on filesystems with a 32000 subdirectories + limit (like <literal>ext3</literal>).</para></listitem> + + </varlistentry> + + <varlistentry><term><option>--max-atime</option> <replaceable>atime</replaceable></term> + + <listitem><para>Only delete a store path if its last-accessed time + is less than <replaceable>atime</replaceable>. This allows you to + garbage-collect only packages that haven’t been used recently. + The time is expressed as the number of seconds in the Unix epoch, + i.e., since 1970-01-01 00:00:00 UTC. An easy way to convert to + this format is <literal>date +%s -d "<replaceable>date + specification</replaceable>"</literal>.</para> + + <para>For directories, the last-accessed time is the highest + last-accessed time of any regular file in the directory (or in any + of its subdirectories). That is, the <literal>atime</literal> + field maintained by the filesystem is ignored for directories. + This is because operations such as rebuilding the + <command>locate</command> database tend to update the + <literal>atime</literal> values of all directories, so they’re not + a useful indicator of whether a package was recently used.</para> + + <para>Note that <command>nix-store --optimise</command> reads all + regular files in the Nix store, and so causes all last-accessed + times to be set to the present time. This makes + <option>--max-atime</option> ineffective (for a while at + least).</para></listitem> + + </varlistentry> + + <varlistentry><term><option>--use-atime</option></term> + + <listitem><para>Delete store paths in order of ascending + last-accessed time. This is useful in conjunction with the other + options to delete only the least recently used + packages.</para></listitem> + + </varlistentry> + +</variablelist> + +</para> + +<para>The behaviour of the collector is also influenced by the <link linkend="conf-gc-keep-outputs"><literal>gc-keep-outputs</literal></link> and <link linkend="conf-gc-keep-derivations"><literal>gc-keep-derivations</literal></link> @@ -284,6 +357,20 @@ deleting `/nix/store/kq82idx6g0nyzsp2s14gfsc38npai7lf-cairo-1.0.4.tar.gz.drv' </para> +<para>To delete unreachable paths not accessed in the last two months: + +<screen> +$ nix-store --gc -v --max-atime $(date +%s -d "2 months ago")</screen> + +</para> + +<para>To delete at least 100 MiBs of unreachable paths: + +<screen> +$ nix-store --gc --max-freed $((100 * 1024 * 1024))</screen> + +</para> + </refsection> @@ -950,7 +1037,51 @@ ktorrent-2.2.1/NEWS </refsection> -<!-- TODO: export, import operations --> +<!--######################################################################--> + +<refsection><title>Operation <option>--dump-db</option></title> + +<refsection> + <title>Synopsis</title> + <cmdsynopsis> + <command>nix-store</command> + <arg choice='plain'><option>--dump-db</option></arg> + </cmdsynopsis> +</refsection> + +<refsection><title>Description</title> + +<para>The operation <option>--dump-db</option> writes a dump of the +Nix database to standard output. It can be loaded into an empty Nix +store using <option>--load-db</option>. This is useful for making +backups and when migrating to different database schemas.</para> + +</refsection> + +</refsection> + + +<!--######################################################################--> + +<refsection><title>Operation <option>--dump-db</option></title> + +<refsection> + <title>Synopsis</title> + <cmdsynopsis> + <command>nix-store</command> + <arg choice='plain'><option>--load-db</option></arg> + </cmdsynopsis> +</refsection> + +<refsection><title>Description</title> + +<para>The operation <option>--load-db</option> reads a dump of the Nix +database created by <option>--dump-db</option> from standard input and +loads it into the Nix database.</para> + +</refsection> + +</refsection> </refentry> |