diff options
Diffstat (limited to 'man/systemd.special.xml')
| -rw-r--r-- | man/systemd.special.xml | 37 |
1 files changed, 27 insertions, 10 deletions
diff --git a/man/systemd.special.xml b/man/systemd.special.xml index 0a37f65956..055d854555 100644 --- a/man/systemd.special.xml +++ b/man/systemd.special.xml @@ -204,12 +204,22 @@ <varlistentry> <term><filename>emergency.target</filename></term> <listitem> - <para>A special target unit that starts an emergency shell - on the main console. This unit is supposed to be used with - the kernel command line option - <varname>systemd.unit=</varname> and has otherwise little - use. - </para> + <para>A special target unit that starts an emergency shell on the main console. This target does not pull in + any serices or mounts. It is the most minimal version of starting the system in order to acquire an + interactive shell; the only processes running are usually just the system manager (PID 1) and the shell + process. This unit is supposed to be used with the kernel command line option + <varname>systemd.unit=</varname>; it is also used when a file system check on a required file system fails, + and boot-up cannot continue. Compare with <filename>rescue.target</filename>, which serves a similar purpose, + but also starts the most basic services and mounts all file systems.</para> + + <para>Use the <literal>systemd.unit=emergency.target</literal> kernel command line option to boot into this + mode. A short alias for this kernel command line option is <literal>emergency</literal>, for compatibility + with SysV.</para> + + <para>In many ways booting into <filename>emergency.target</filename> is similar to the effect of booting + with <literal>init=/bin/sh</literal> on the kernel command line, except that emergency mode provides you with + the full system and service manager, and allows starting individual units in order to continue the boot + process in steps.</para> </listitem> </varlistentry> <varlistentry> @@ -440,11 +450,18 @@ <varlistentry> <term><filename>rescue.target</filename></term> <listitem> - <para>A special target unit for setting up the base system - and a rescue shell.</para> + <para>A special target unit that pulls in the base system (including system mounts) and spawns a rescue + shell. Isolate to this target in order to administer the system in single-user mode with all file systems + mounted but with no services running, except for the most basic. Compare with + <filename>emergency.target</filename>, which is much more reduced and does not provide the file systems or + most basic services.</para> - <para><filename>runlevel1.target</filename> is an alias for - this target unit, for compatibility with SysV.</para> + <para><filename>runlevel1.target</filename> is an alias for this target unit, for compatibility with + SysV.</para> + + <para>Use the <literal>systemd.unit=rescue.target</literal> kernel command line option to boot into this + mode. A short alias for this kernel command line option is <literal>1</literal>, for compatibility with + SysV.</para> </listitem> </varlistentry> <varlistentry> |