diff options
Diffstat (limited to 'man')
| -rw-r--r-- | man/bootup.xml | 143 | ||||
| -rw-r--r-- | man/systemd.special.xml | 258 |
2 files changed, 261 insertions, 140 deletions
diff --git a/man/bootup.xml b/man/bootup.xml index 65923528d4..a596e85b70 100644 --- a/man/bootup.xml +++ b/man/bootup.xml @@ -50,18 +50,20 @@ <refsect1> <title>Description</title> - <para>A number of different components are involved in the - system boot. Immediately after power-up, the system - BIOS will do minimal hardware initialization, and hand - control over to a boot loader stored on a persistent - storage device. This boot loader will then invoke an - OS kernel from disk (or the network). In the Linux - case this kernel now (optionally) extracts and + <para>A number of different components are involved in + the system boot. Immediately after power-up, the + system BIOS will do minimal hardware initialization, + and hand control over to a boot loader stored on a + persistent storage device. This boot loader will then + invoke an OS kernel from disk (or the network). In the + Linux case this kernel (optionally) extracts and executes an initial RAM disk image (initrd) such as <citerefentry><refentrytitle>dracut</refentrytitle><manvolnum>8</manvolnum></citerefentry> - which looks for the root file system. After the root - file system is found and mounted the initrd hands over - control to the system manager (such as + which looks for the root file system (possibly using + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> + for this). After the root file system is found and + mounted the initrd hands over control to the host's + system manager (such as <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>) stored on the OS image which is then responsible for probing all remaining hardware, mounting all necessary @@ -132,35 +134,35 @@ v sysinit.target | - _________________/|\___________________ - / | \ - | | | - v | v - (various | rescue.service - sockets...) | | - | | v - v | <emphasis>rescue.target</emphasis> - sockets.target | - | | - \_________________ | - \| + ____________________________________/|\________________________________________ + / | | | \ + | | | | | + v v | v v + (various (various | (various rescue.service + timers...) paths...) | sockets...) | + | | | | v + v v | v <emphasis>rescue.target</emphasis> + timers.target paths.target | sockets.target + | | | | + \__________________|_________________ | ___________________/ + \|/ v basic.target | - __________________________________/| emergency.service - / | | | - | | | v - v v v <emphasis>emergency.target</emphasis> - display- (various system (various system - manager.service services services) - | required for | - | graphical UIs) v - | | <emphasis>multi-user.target</emphasis> - | | | - \_______________ | _________________/ + ____________________________________/| emergency.service + / | | | + | | | v + v v v <emphasis>emergency.target</emphasis> + display- (various system (various system + manager.service services services) + | required for | + | graphical UIs) v + | | <emphasis>multi-user.target</emphasis> + | | | + \_________________ | _________________/ \|/ v - <emphasis>graphical.target</emphasis></programlisting> + <emphasis>graphical.target</emphasis></programlisting> <para>Target units that are commonly used as boot targets are <emphasis>emphasized</emphasis>. These @@ -174,23 +176,41 @@ </refsect1> <refsect1> - <title>Initrd System Manager Bootup</title> - <para>The default target in the initrd is the initrd.target. The bootup process is - identical to the System Manager Bootup until it reaches basic.target. From there, - systemd approaches the special initrd.target. If the root device can be mounted at - /sysroot, the sysroot.mount unit becomes active and the initrd-root-fs.target is - reached. - The initrd-parse-etc.service scans /sysroot/etc/fstab for a possible /usr mountpoint - and additional entries marked with the <emphasis>x-initrd.mount</emphasis> option. - All entries found are mounted below /sysroot, and the initrd-fs.target is reached. - The initrd-cleanup.service isolates to the initrd-switch-root.target, where cleanup - services can run. As the very last step, the initrd-switch-root.service is activated, - which will cause the system to switch its root to /sysroot. + <title>Bootup in the Initial RAM Disk (initrd)</title> + <para>The initial RAM disk implementation (initrd) can + be set up using systemd as well. In this case boot up + inside the initrd follows the following + structure.</para> + + <para>The default target in the initrd is + <filename>initrd.target</filename>. The bootup process + begins identical to the system manager bootup (see + above) until it reaches + <filename>basic.target</filename>. From there, systemd + approaches the special target + <filename>initrd.target</filename>. If the root device + can be mounted at <filename>/sysroot</filename>, the + <filename>sysroot.mount</filename> unit becomes active + and <filename>initrd-root-fs.target</filename> is + reached. The service + <filename>initrd-parse-etc.service</filename> scans + <filename>/sysroot/etc/fstab</filename> for a possible + <filename>/usr</filename> mount point and additional + entries marked with the + <emphasis>x-initrd.mount</emphasis> option. All + entries found are mounted below + <filename>/sysroot</filename>, and + <filename>initrd-fs.target</filename> is reached. The + service <filename>initrd-cleanup.service</filename> + isolates to the + <filename>initrd-switch-root.target</filename>, where + cleanup services can run. As the very last step, the + <filename>initrd-switch-root.service</filename> is + activated, which will cause the system to switch its + root to <filename>/sysroot</filename>. </para> -<programlisting> - (identical to System Manager Bootup) - : +<programlisting> : (beginning identical to above) : v basic.target @@ -203,13 +223,13 @@ | initrd-root-fs.target | | | v - | initrd-parse-etc.service - (custom initrd services) | - | v + v initrd-parse-etc.service + (custom initrd | + services...) v | (sysroot-usr.mount and | various mounts marked | with fstab option - | x-initrd.mount) + | x-initrd.mount...) | | | v | initrd-fs.target @@ -225,11 +245,11 @@ | v ______________________/| - / | + / v | initrd-udevadm-cleanup-db.service - | | - (custom initrd services) | - | | + v | + (custom initrd | + services...) | \______________________ | \| v @@ -239,17 +259,16 @@ initrd-switch-root.service | v - switch-root -</programlisting> + Transition to Host OS</programlisting> </refsect1> <refsect1> <title>System Manager Shutdown</title> - <para>System shutdown also consists of various target - units with some minimal ordering structure - applied:</para> + <para>System shutdown with systemd also consists of + various target units with some minimal ordering + structure applied:</para> diff --git a/man/systemd.special.xml b/man/systemd.special.xml index 67a81b639b..8a7242662d 100644 --- a/man/systemd.special.xml +++ b/man/systemd.special.xml @@ -73,6 +73,7 @@ <filename>network.target</filename>, <filename>nss-lookup.target</filename>, <filename>nss-user-lookup.target</filename>, + <filename>paths.target</filename>, <filename>poweroff.target</filename>, <filename>printer.target</filename>, <filename>reboot.target</filename>, @@ -97,6 +98,7 @@ <filename>syslog.socket</filename>, <filename>system-update.target</filename>, <filename>time-sync.target</filename>, + <filename>timers.target</filename>, <filename>umount.target</filename></para> </refsynopsisdiv> @@ -116,22 +118,23 @@ <term><filename>basic.target</filename></term> <listitem> <para>A special target unit - covering early boot-up.</para> + covering basic boot-up.</para> <para>systemd automatically adds dependencies of the types - Requires and After for this - target unit to all SysV - service units configured for - runlevel 1 to 5.</para> - <para>Usually this should pull-in - all sockets, mount points, - swap devices and other basic + <varname>Requires=</varname> + and <varname>After=</varname> + for this target unit to all + services (except for those + with + <varname>DefaultDependencies=no</varname>).</para> + + <para>Usually this should + pull-in all mount points, swap + devices, sockets, timers, and + path units and other basic initialization necessary for - the general purpose - daemons. Most normal daemons - should have dependencies of - type After and Requires on - this unit.</para> + general purpose + daemons.</para> </listitem> </varlistentry> <varlistentry> @@ -139,9 +142,15 @@ <listitem> <para>This target is started automatically as soon as a - bluetooth controller is + Bluetooth controller is plugged in or becomes available at boot.</para> + + <para>This may be used to pull + in Bluetooth management + daemons dynamically when + Bluetooth hardware is + found.</para> </listitem> </varlistentry> <varlistentry> @@ -169,7 +178,7 @@ <term><filename>dbus.service</filename></term> <listitem> <para>A special unit for the - D-Bus system bus. As soon as + D-Bus bus daemon. As soon as this service is fully started up systemd will connect to it and register its @@ -182,7 +191,7 @@ <para>A special unit for the D-Bus system bus socket. All units with - <literal>Type=dbus</literal> + <varname>Type=dbus</varname> automatically gain a dependency on this unit.</para> @@ -198,6 +207,7 @@ <filename>multi-user.target</filename> or <filename>graphical.target</filename>.</para> + <para>The default unit systemd starts at bootup can be overridden with the @@ -247,8 +257,10 @@ <term><filename>getty.target</filename></term> <listitem> <para>A special target unit - that pulls in all local TTY - <filename>getty</filename> instances. + that pulls in statically + configured local TTY + <filename>getty</filename> + instances. </para> </listitem> </varlistentry> @@ -261,11 +273,17 @@ <filename>multi-user.target</filename>.</para> <para>Units that are needed - for graphical login shall add - Wants dependencies for their - unit to this unit (or + for graphical logins shall add + <varname>Wants=</varname> + dependencies for their unit to + this unit (or <filename>multi-user.target</filename>) - during installation.</para> + during installation. This is + best configured via + <varname>WantedBy=graphical.target</varname> + in the unit's + <literal>[Install]</literal> + section.</para> </listitem> </varlistentry> <varlistentry> @@ -290,7 +308,13 @@ <term><filename>halt.target</filename></term> <listitem> <para>A special target unit - for shutting down and halting the system.</para> + for shutting down and halting + the system. Note that this + target is distinct from + <filename>poweroff.target</filename> + in that it generally really + just halts the system rather + than powering it down.</para> <para>Applications wanting to halt the system should start @@ -300,16 +324,17 @@ <varlistentry> <term><filename>initrd-fs.target</filename></term> <listitem> - <para>systemd automatically - adds dependencies of type - Before to sysroot-usr.mount and - all mount points fround in + <para><citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>3</manvolnum></citerefentry> + automatically adds + dependencies of type + <varname>Before=</varname> to + <filename>sysroot-usr.mount</filename> + and all mount points fround in <filename>/etc/fstab</filename> that have the <option>auto</option> and <option>x-initrd.mount</option> mount options set. - See also <literal>systemd-fstab-generator</literal>. </para> </listitem> </varlistentry> @@ -338,20 +363,21 @@ <varlistentry> <term><filename>local-fs.target</filename></term> <listitem> - <para>systemd automatically + <para><citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>3</manvolnum></citerefentry> + automatically adds + dependencies of type + <varname>Before=</varname> to + all mount units that refer to + local mount points for this + target unit. In addition, it adds dependencies of type - After to all mount units that - refer to local mount points - for this target unit. In - addition, systemd adds - dependencies of type Wants to + <varname>Wants=</varname> to this target unit for those mounts listed in <filename>/etc/fstab</filename> that have the - <option>auto</option> and - <option>comment=systemd.mount</option> - mount options set.</para> + <option>auto</option> mount + option set.</para> </listitem> </varlistentry> <varlistentry> @@ -377,9 +403,15 @@ <para>Units that are needed for a multi-user system shall - add Wants dependencies to - this unit for their unit during - installation.</para> + add <varname>Wants=</varname> + dependencies for their unit to + this unit during + installation. This is best + configured via + <varname>WantedBy=multi-uer.target</varname> + in the unit's + <literal>[Install]</literal> + section.</para> </listitem> </varlistentry> <varlistentry> @@ -387,10 +419,10 @@ <listitem> <para>systemd automatically adds dependencies of type - After for this target unit to - all SysV init script service - units with an LSB header - referring to the + <varname>After=</varname> for + this target unit to all SysV + init script service units with + an LSB header referring to the <literal>$network</literal> facility.</para> @@ -418,7 +450,8 @@ <filename>nss-user-lookup.target</filename> should be used. systemd automatically adds - dependencies of type After for + dependencies of type + <varname>After=</varname> for this target unit to all SysV init script service units with an LSB header referring to the @@ -441,6 +474,29 @@ </listitem> </varlistentry> <varlistentry> + <term><filename>paths.target</filename></term> + <listitem> + <para>A special target unit + that sets up all path units + (see + <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details) that shall be + active after boot.</para> + + <para>It is recommended that + path units installed by + applications get pulled in via + <varname>Wants=</varname> + dependencies from this + unit. This is best configured + via a + <varname>WantedBy=paths.target</varname> + in the path unit's + <literal>[Install]</literal> + section.</para> + </listitem> + </varlistentry> + <varlistentry> <term><filename>poweroff.target</filename></term> <listitem> <para>A special target unit @@ -463,6 +519,12 @@ printer is plugged in or becomes available at boot.</para> + + <para>This may be used to pull + in printer management + daemons dynamically when + printer hardware is + found.</para> </listitem> </varlistentry> <varlistentry> @@ -490,10 +552,10 @@ <para>systemd automatically adds dependencies of type - After for this target unit to - all SysV init script service - units with an LSB header - referring to the + <varname>After=</varname> for + this target unit to all SysV + init script service units with + an LSB header referring to the <literal>$remote_fs</literal> facility.</para> </listitem> @@ -525,11 +587,14 @@ <varlistentry> <term><filename>initrd-root-fs.target</filename></term> <listitem> - <para>systemd automatically - adds dependencies of type - Before to the sysroot.mount unit, - which is generated from the kernel command - line by the <literal>systemd-fstab-generator</literal>. + <para><citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>3</manvolnum></citerefentry> + automatically adds + dependencies of type + <varname>Before=</varname> to + the + <filename>sysroot.mount</filename> + unit, which is generated from + the kernel command line. </para> </listitem> </varlistentry> @@ -538,10 +603,10 @@ <listitem> <para>systemd automatically adds dependencies of type - After for this target unit to - all SysV init script service - units with an LSB header - referring to the + <varname>After=</varname> for + this target unit to all SysV + init script service units with + an LSB header referring to the <literal>$portmap</literal> facility.</para> </listitem> @@ -574,20 +639,12 @@ <para>Services that shall be terminated on system shutdown - shall add Conflicts + shall add <varname>Conflicts=</varname> dependencies to this unit for their service unit, which is implicitly done when <varname>DefaultDependencies=yes</varname> is set (the default).</para> - - <para>systemd automatically - adds dependencies of type - Conflicts to this target unit - for all SysV init script - service units that shall be - terminated in SysV runlevels 0 - or 6.</para> </listitem> </varlistentry> <varlistentry> @@ -607,7 +664,9 @@ <para>A special target unit that is pulled in by <filename>suspend.target</filename>, - <filename>hibernate.target</filename> and <filename>hybrid-sleep.target</filename> + <filename>hibernate.target</filename> + and + <filename>hybrid-sleep.target</filename> and may be used to hook units into the sleep state logic.</para> @@ -621,20 +680,35 @@ smartcard controller is plugged in or becomes available at boot.</para> + + <para>This may be used to pull + in printer management + daemons dynamically when + smartcard hardware is + found.</para> </listitem> </varlistentry> <varlistentry> <term><filename>sockets.target</filename></term> <listitem> <para>A special target unit - that sets up all service - sockets.</para> + that sets up all socket + units.(see + <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details) that shall be + active after boot.</para> <para>Services that can be socket-activated shall add - Wants dependencies to this - unit for their socket unit - during installation.</para> + <varname>Wants=</varname> + dependencies to this unit for + their socket unit during + installation. This is best + configured via a + <varname>WantedBy=sockets.target</varname> + in the socket unit's + <literal>[Install]</literal> + section.</para> </listitem> </varlistentry> <varlistentry> @@ -645,6 +719,11 @@ sound card is plugged in or becomes available at boot.</para> + + <para>This may be used to pull + in audio management daemons + dynamically when printer + hardware is found.</para> </listitem> </varlistentry> <varlistentry> @@ -710,15 +789,38 @@ <listitem> <para>systemd automatically adds dependencies of type - After for this target unit to - all SysV init script service - units with an LSB header - referring to the + <varname>After=</varname> for + this target unit to all SysV + init script service units with + an LSB header referring to the <literal>$time</literal> facility.</para> </listitem> </varlistentry> <varlistentry> + <term><filename>timers.target</filename></term> + <listitem> + <para>A special target unit + that sets up all timer + units (see + <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details) that shall be + active after boot.</para> + + <para>It is recommended that + timer units installed by + applications get pulled in via + <varname>Wants=</varname> + dependencies from this + unit. This is best configured + via + <varname>WantedBy=timers.target</varname> + in the timer unit's + <literal>[Install]</literal> + section.</para> + </listitem> + </varlistentry> + <varlistentry> <term><filename>umount.target</filename></term> <listitem> <para>A special target unit @@ -788,7 +890,7 @@ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry> + <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> </para> </refsect1> |