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Diffstat (limited to 'man/systemd-machine-id-commit.service.xml')
| -rw-r--r-- | man/systemd-machine-id-commit.service.xml | 57 |
1 files changed, 26 insertions, 31 deletions
diff --git a/man/systemd-machine-id-commit.service.xml b/man/systemd-machine-id-commit.service.xml index 7c8fc0874e..39da1922cc 100644 --- a/man/systemd-machine-id-commit.service.xml +++ b/man/systemd-machine-id-commit.service.xml @@ -42,55 +42,50 @@ <refnamediv> <refname>systemd-machine-id-commit.service</refname> - <refpurpose>Commit transient machine-id to disk</refpurpose> + <refpurpose>Commit a transient machine ID to disk</refpurpose> </refnamediv> <refsynopsisdiv> <para><filename>systemd-machine-id-commit.service</filename></para> - <para><filename>/usr/lib/systemd/systemd-machine-id-commit</filename></para> </refsynopsisdiv> <refsect1> <title>Description</title> - <para><filename>systemd-machine-id-commit.service</filename> is a - service responsible for committing any transient - <filename>/etc/machine-id</filename> file to a writable file + <para><filename>systemd-machine-id-commit.service</filename> is an + early boot service responsible for committing transient + <filename>/etc/machine-id</filename> files to a writable disk file system. See <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for more information about this file.</para> - - <para>This service is started shortly after - <filename>local-fs.target</filename> if - <filename>/etc/machine-id</filename> is an independent mount point - (probably a tmpfs one) and /etc is writable. - <command>systemd-machine-id-commit</command> will then write - current machine ID to disk and unmount the transient + for more information about machine IDs.</para> + + <para>This service is started after + <filename>local-fs.target</filename> in case + <filename>/etc/machine-id</filename> is a mount point of its own + (usually from a memory file system such as + <literal>tmpfs</literal>) and /etc is writable. The service will + invoke <command>systemd-machine-id-setup --commit</command>, which + writes the current transient machine ID to disk and unmount the <filename>/etc/machine-id</filename> file in a race-free manner to - ensure that file is always valid for other processes.</para> - - <para>Note that the traditional way to initialize the machine ID - in <filename>/etc/machine-id</filename> is to use - <command>systemd-machine-id-setup</command> by system installer - tools. You can also use - <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> - to initialize the machine ID on mounted (but not booted) system - images. The main use case for that service is - <filename>/etc/machine-id</filename> being an empty file at boot - and initrd chaining to systemd giving it a read only file system - that will be turned read-write later during the boot - process.</para> - - <para>There is no consequence if that service fails other than a - newer machine-id will be generated during next system boot. - </para> + ensure that file is always valid and accessible for other + processes. See + <citerefentry><refentrytitle>systemd-machine-id-setup</refentrytitle><manvolnum>1</manvolnum></citerefentry> + for details.</para> + + <para>The main use case of this service are systems where + <filename>/etc/machine-id</filename> is read-only and initially + not initialized. In this case, the system manager will generate a + transient machine ID file on a memory file system, and mount it + over <filename>/etc/machine-id</filename>, during the early boot + phase. This service is then invoked in a later boot phase, as soon + as <filename>/etc</filename> has been remounted writable and the + ID may thus be committed to disk to make it permanent.</para> </refsect1> <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd-machine-id-commit</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-machine-id-setup</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> |