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- <a href="../libudev/index.html">gudev </a><span style="float:right">systemd 20
4</span><hr><div class="refentry"><a name="systemd.exec"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>systemd.exec — Execution environment configuration</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><p><code class="filename"><em class="replaceable"><code>service</code></em>.service</code>,
+ <a href="../libudev/index.html">gudev </a><span style="float:right">systemd 20
8</span><hr><div class="refentry"><a name="systemd.exec"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>systemd.exec — Execution environment configuration</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><p><code class="filename"><em class="replaceable"><code>service</code></em>.service</code>,
<code class="filename"><em class="replaceable"><code>socket</code></em>.socket</code>,
<code class="filename"><em class="replaceable"><code>mount</code></em>.mount</code>,
- <code class="filename"><em class="replaceable"><code>swap</code></em>.swap</code></p></div><div class="refsect1"><a name="idm2
59787182016"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p>Unit configuration files for services, sockets,
- mount points and swap devices share a subset of
+ <code class="filename"><em class="replaceable"><code>swap</code></em>.swap</code></p></div><div class="refsect1"><a name="idm2
74706676192"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p>Unit configuration files for services, sockets,
+ mount points, and swap devices share a subset of
configuration options which define the execution
environment of spawned processes.</p><p>This man page lists the configuration options
shared by these four unit types. See
files, and
<a href="systemd.service.html"><span class="citerefentry"><span class="refentrytitle">systemd.service</span>(5)</span></a>,
<a href="systemd.socket.html"><span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span></a>,
- <a href="systemd.swap.html"><span class="citerefentry"><span class="refentrytitle">systemd.swap</span>(5)</span></a>
+ <a href="systemd.swap.html"><span class="citerefentry"><span class="refentrytitle">systemd.swap</span>(5)</span></a>,
and
<a href="systemd.mount.html"><span class="citerefentry"><span class="refentrytitle">systemd.mount</span>(5)</span></a>
for more information on the specific unit
configuration files. The execution specific
configuration options are configured in the [Service],
[Socket], [Mount], or [Swap] sections, depending on the unit
- type.</p></div><div class="refsect1"><a name="idm2
59787175536"></a><h2 id="Options">Options<a class="headerlink" title="Permalink to this headline" href="#Options">¶</a></h2><div class="variablelist"><dl class="variablelist"><dt id="WorkingDirectory="><span class="term"><code class="varname">WorkingDirectory=</code></span><a class="headerlink" title="Permalink to this term" href="#WorkingDirectory=">¶</a></dt><dd><p>Takes an absolute
+ type.</p></div><div class="refsect1"><a name="idm2
74706543616"></a><h2 id="Options">Options<a class="headerlink" title="Permalink to this headline" href="#Options">¶</a></h2><div class="variablelist"><dl class="variablelist"><dt id="WorkingDirectory="><span class="term"><code class="varname">WorkingDirectory=</code></span><a class="headerlink" title="Permalink to this term" href="#WorkingDirectory=">¶</a></dt><dd><p>Takes an absolute
directory path. Sets the working
directory for executed processes. If
- not set defaults to the root directory
+ not set, defaults to the root directory
when systemd is running as a system
instance and the respective user's
home directory if run as
directory for executed processes, with
the
<a href="chroot.html"><span class="citerefentry"><span class="refentrytitle">chroot</span>(2)</span></a>
- system call. If this is used it must
+ system call. If this is used, it must
be ensured that the process and all
its auxiliary files are available in
the <code class="function">chroot()</code>
set, the default group of the user is
chosen.</p></dd><dt id="SupplementaryGroups="><span class="term"><code class="varname">SupplementaryGroups=</code></span><a class="headerlink" title="Permalink to this term" href="#SupplementaryGroups=">¶</a></dt><dd><p>Sets the supplementary
Unix groups the processes are executed
- as. This takes a space separated list
+ as. This takes a space-separated list
of group names or IDs. This option may
be specified more than once in which
case all listed groups are set as
between -1000 (to disable OOM killing
for this process) and 1000 (to make
killing of this process under memory
- pressure very likely). See <a class="ulink" href="http://www.kernel.org/doc/Documentation/filesystems/proc.txt" target="_top">proc.txt</a>
+ pressure very likely). See <a class="ulink" href="https://www.kernel.org/doc/Documentation/filesystems/proc.txt" target="_top">proc.txt</a>
for details.</p></dd><dt id="IOSchedulingClass="><span class="term"><code class="varname">IOSchedulingClass=</code></span><a class="headerlink" title="Permalink to this term" href="#IOSchedulingClass=">¶</a></dt><dd><p>Sets the IO scheduling
class for executed processes. Takes an
integer between 0 and 3 or one of the
See <a href="sched_setscheduler.html"><span class="citerefentry"><span class="refentrytitle">sched_setscheduler</span>(2)</span></a>
for details.
</p></dd><dt id="CPUSchedulingResetOnFork="><span class="term"><code class="varname">CPUSchedulingResetOnFork=</code></span><a class="headerlink" title="Permalink to this term" href="#CPUSchedulingResetOnFork=">¶</a></dt><dd><p>Takes a boolean
- argument. If true elevated CPU
+ argument. If true, elevated CPU
scheduling priorities and policies
will be reset when the executed
processes fork, and can hence not leak
be specified more than once in which
case the specificed CPU affinity masks
are merged. If the empty string is
- assigned the mask is reset, all
+ assigned, the mask is reset, all
assignments prior to this will have no
effect. See
<a href="sched_setaffinity.html"><span class="citerefentry"><span class="refentrytitle">sched_setaffinity</span>(2)</span></a>
option may be specified more than once
in which case all listed variables
will be set. If the same variable is
- set twice the later setting will
+ set twice, the later setting will
override the earlier setting. If the
empty string is assigned to this
- option the list of environment
+ option, the list of environment
variables is reset, all prior
assignments have no effect.
Variable expansion is not performed
- inside the strings, and $ has no special
- meaning.
+ inside the strings, however, specifier
+ expansion is possible. The $ character has
+ no special meaning.
If you need to assign a value containing spaces
to a variable, use double quotes (")
for the assignment.</p><p>Example:
</p><pre class="programlisting">Environment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</pre><p>
- gives three variables <code class="literal">VAR1</code>,
- <code class="literal">VAR2</code>, <code class="literal">VAR3</code>.
+ gives three variables "<code class="literal">VAR1</code>",
+ "<code class="literal">VAR2</code>", "<code class="literal">VAR3</code>".
</p><p>
See
<a href="environ.html"><span class="citerefentry"><span class="refentrytitle">environ</span>(7)</span></a>
<code class="varname">Environment=</code> but
reads the environment variables from a
text file. The text file should
- contain new-line separated variable
+ contain new-line-separated variable
assignments. Empty lines and lines
starting with ; or # will be ignored,
which may be used for commenting. A line
and trailing whitespace from the values
of assignments, unless you use
double quotes (").</p><p>The argument passed should be an
- absolute file name or wildcard
+ absolute filename or wildcard
expression, optionally prefixed with
- "-", which indicates that if the file
- does not exist it won't be read and no
- error or warning message is logged.
- This option may be specified more than
- once in which case all specified files
- are read. If the empty string is
- assigned to this option the list of
- file to read is reset, all prior
- assignments have no effect.</p><p>The files listed with this
+ "<code class="literal">-</code>", which indicates
+ that if the file does not exist, it
+ will not be read and no error or warning
+ message is logged. This option may be
+ specified more than once in which case
+ all specified files are read. If the
+ empty string is assigned to this
+ option, the list of file to read is
+ reset, all prior assignments have no
+ effect.</p><p>The files listed with this
directive will be read shortly before
the process is executed. Settings from
these files override settings made
with
<code class="varname">Environment=</code>. If
the same variable is set twice from
- these files the files will be read in
+ these files, the files will be read in
the order they are specified and the
later setting will override the
earlier setting.</p></dd><dt id="StandardInput="><span class="term"><code class="varname">StandardInput=</code></span><a class="headerlink" title="Permalink to this term" href="#StandardInput=">¶</a></dt><dd><p>Controls where file
<code class="option">tty-force</code>,
<code class="option">tty-fail</code> or
<code class="option">socket</code>. If
- <code class="option">null</code> is selected
+ <code class="option">null</code> is selected,
standard input will be connected to
<code class="filename">/dev/null</code>,
i.e. all read attempts by the process
will result in immediate EOF. If
- <code class="option">tty</code> is selected
+ <code class="option">tty</code> is selected,
standard input is connected to a TTY
(as configured by
<code class="varname">TTYPath=</code>, see
below) and the executed process
becomes the controlling process of the
terminal. If the terminal is already
- being controlled by another process the
+ being controlled by another process, the
executed process waits until the current
controlling process releases the
terminal.
file (see
<a href="systemd.socket.html"><span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span></a>
for details) specifies a single socket
- only. If this option is set standard
+ only. If this option is set, standard
input will be connected to the socket
the service was activated from, which
is primarily useful for compatibility
<code class="option">kmsg+console</code>,
<code class="option">journal+console</code> or
<code class="option">socket</code>. If set to
- <code class="option">inherit</code> the file
+ <code class="option">inherit</code>, the file
descriptor of standard input is
duplicated for standard output. If set
- to <code class="option">null</code> standard
+ to <code class="option">null</code>, standard
output will be connected to
<code class="filename">/dev/null</code>,
i.e. everything written to it will be
- lost. If set to <code class="option">tty</code>
+ lost. If set to <code class="option">tty</code>,
standard output will be connected to a
tty (as configured via
<code class="varname">TTYPath=</code>, see
below). If the TTY is used for output
- only the executed process will not
+ only, the executed process will not
become the controlling process of the
terminal, and will not fail or wait
for other processes to release the
device specified with
<code class="varname">TTYPath=</code> before and
after execution. Defaults to
-
<code class="literal">no</code>.</p></dd><dt id="TTYVHangup="><span class="term"><code class="varname">TTYVHangup=</code></span><a class="headerlink" title="Permalink to this term" href="#TTYVHangup=">¶</a></dt><dd><p>Disconnect all clients
+
"<code class="literal">no</code>".</p></dd><dt id="TTYVHangup="><span class="term"><code class="varname">TTYVHangup=</code></span><a class="headerlink" title="Permalink to this term" href="#TTYVHangup=">¶</a></dt><dd><p>Disconnect all clients
which have opened the terminal device
specified with
<code class="varname">TTYPath=</code>
before and after execution. Defaults
to
-
<code class="literal">no</code>.</p></dd><dt id="TTYVTDisallocate="><span class="term"><code class="varname">TTYVTDisallocate=</code></span><a class="headerlink" title="Permalink to this term" href="#TTYVTDisallocate=">¶</a></dt><dd><p>If the terminal
+
"<code class="literal">no</code>".</p></dd><dt id="TTYVTDisallocate="><span class="term"><code class="varname">TTYVTDisallocate=</code></span><a class="headerlink" title="Permalink to this term" href="#TTYVTDisallocate=">¶</a></dt><dd><p>If the terminal
device specified with
<code class="varname">TTYPath=</code> is a
- virtual console terminal try to
+ virtual console terminal, try to
deallocate the TTY before and after
execution. This ensures that the
screen and scrollback buffer is
cleared. Defaults to
-
<code class="literal">no</code>.</p></dd><dt id="SyslogIdentifier="><span class="term"><code class="varname">SyslogIdentifier=</code></span><a class="headerlink" title="Permalink to this term" href="#SyslogIdentifier=">¶</a></dt><dd><p>Sets the process name
+
"<code class="literal">no</code>".</p></dd><dt id="SyslogIdentifier="><span class="term"><code class="varname">SyslogIdentifier=</code></span><a class="headerlink" title="Permalink to this term" href="#SyslogIdentifier=">¶</a></dt><dd><p>Sets the process name
to prefix log lines sent to syslog or
- the kernel log buffer with. If not set
+ the kernel log buffer with. If not set,
defaults to the process name of the
executed process. This option is only
useful when
<code class="varname">infinity</code> to
configure no limit on a specific
resource.</p></dd><dt id="PAMName="><span class="term"><code class="varname">PAMName=</code></span><a class="headerlink" title="Permalink to this term" href="#PAMName=">¶</a></dt><dd><p>Sets the PAM service
- name to set up a session as. If set
+ name to set up a session as. If set,
the executed process will be
registered as a PAM session under the
specified service name. This is only
useful in conjunction with the
<code class="varname">User=</code> setting. If
- not set no PAM session will be opened
+ not set, no PAM session will be opened
for the executed processes. See
<a href="pam.html"><span class="citerefentry"><span class="refentrytitle">pam</span>(8)</span></a>
for details.</p></dd><dt id="TCPWrapName="><span class="term"><code class="varname">TCPWrapName=</code></span><a class="headerlink" title="Permalink to this term" href="#TCPWrapName=">¶</a></dt><dd><p>If this is a
- socket-activated service this sets the
+ socket-activated service, this sets the
tcpwrap service name to check the
permission for the current connection
with. This is only useful in
socket types (e.g. datagram/UDP) and
on processes unrelated to socket-based
activation. If the tcpwrap
- verification fails daemon start-up
+ verification fails, daemon start-up
will fail and the connection is
terminated. See
<a href="tcpd.html"><span class="citerefentry"><span class="refentrytitle">tcpd</span>(8)</span></a>
capability bounding set for the
executed process. See
<a href="capabilities.html"><span class="citerefentry"><span class="refentrytitle">capabilities</span>(7)</span></a>
- for details. Takes a whitespace
- separated list of capability names as
- read by
+ for details. Takes a whitespace-separated
+ list of capability names as read by
<a href="cap_from_name.html"><span class="citerefentry"><span class="refentrytitle">cap_from_name</span>(3)</span></a>,
- e.g. <code class="literal">CAP_SYS_ADMIN
- CAP_DAC_OVERRIDE
- CAP_SYS_PTRACE</code>.
+ e.g. <code class="constant">CAP_SYS_ADMIN</code>,
+ <code class="constant">CAP_DAC_OVERRIDE</code>,
+ <code class="constant">CAP_SYS_PTRACE</code>.
Capabilities listed will be included
in the bounding set, all others are
removed. If the list of capabilities
- is prefixed with <code class="literal">~</code>
+ is prefixed with "<code class="literal">~</code>",
all but the listed capabilities will
be included, the effect of the
assignment inverted. Note that this
permitted and inheritable capability
sets, on top of what
<code class="varname">Capabilities=</code>
- does. If this option is not used the
+ does. If this option is not used, the
capability bounding set is not
modified on process execution, hence
no limits on the capabilities of the
appear more than once in which case
the bounding sets are merged. If the
empty string is assigned to this
- option the bounding set is reset to
+ option, the bounding set is reset to
the empty capability set, and all
prior settings have no effect. If set
- to <code class="literal">~</code> (without any
- further argument) the bounding set is
+ to "<code class="literal">~</code>" (without any
+ further argument), the bounding set is
reset to the full set of available
capabilities, also undoing any
previous settings.</p></dd><dt id="SecureBits="><span class="term"><code class="varname">SecureBits=</code></span><a class="headerlink" title="Permalink to this term" href="#SecureBits=">¶</a></dt><dd><p>Controls the secure
option may appear more than once in
which case the secure bits are
ORed. If the empty string is assigned
- to this option the bits are reset to
+ to this option, the bits are reset to
0.</p></dd><dt id="Capabilities="><span class="term"><code class="varname">Capabilities=</code></span><a class="headerlink" title="Permalink to this term" href="#Capabilities=">¶</a></dt><dd><p>Controls the
<a href="capabilities.html"><span class="citerefentry"><span class="refentrytitle">capabilities</span>(7)</span></a>
set for the executed process. Take a
that
<code class="varname">CapabilityBoundingSet=</code>
is probably the much more useful
- setting.</p></dd><dt id="ControlGroup="><span class="term"><code class="varname">ControlGroup=</code></span><a class="headerlink" title="Permalink to this term" href="#ControlGroup=">¶</a></dt><dd><p>Controls the control
- groups the executed processes shall be
- made members of. Takes a
- space-separated list of cgroup
- identifiers. A cgroup identifier is
- formatted like
- <code class="filename">cpu:/foo/bar</code>,
- where "cpu" indicates the kernel
- control group controller used, and
- <code class="filename">/foo/bar</code> is the
- control group path. The controller
- name and ":" may be omitted in which
- case the named systemd control group
- hierarchy is implied. Alternatively,
- the path and ":" may be omitted, in
- which case the default control group
- path for this unit is implied.</p><p>This option may be used to place
- executed processes in arbitrary groups
- in arbitrary hierarchies -- which may
- then be externally configured with
- additional execution limits. By
- default systemd will place all
- executed processes in separate
- per-unit control groups (named after
- the unit) in the systemd named
- hierarchy. This option is primarily
- intended to place executed processes
- in specific paths in specific kernel
- controller hierarchies. It is not
- recommended to manipulate the service
- control group path in the private
- systemd named hierarchy
- (i.e. <code class="literal">name=systemd</code>),
- and doing this might result in
- undefined behaviour. For details about
- control groups see <a class="ulink" href="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt" target="_top">cgroups.txt</a>.</p><p>This option may appear more than
- once, in which case the list of
- control group assignments is
- merged. If the same hierarchy gets two
- different paths assigned only the
- later setting will take effect. If the
- empty string is assigned to this
- option the list of control group
- assignments is reset, all previous
- assignments will have no
- effect.</p><p>Note that the list of control
- group assignments of a unit is
- extended implicitly based on the
- settings of
- <code class="varname">DefaultControllers=</code>
- of
- <a href="systemd-system.conf.html"><span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span></a>,
- but a unit's
- <code class="varname">ControlGroup=</code>
- setting for a specific controller
- takes precedence.</p></dd><dt id="ControlGroupModify="><span class="term"><code class="varname">ControlGroupModify=</code></span><a class="headerlink" title="Permalink to this term" href="#ControlGroupModify=">¶</a></dt><dd><p>Takes a boolean
- argument. If true, the control groups
- created for this unit will be owned by
- the user specified with
- <code class="varname">User=</code> (and the
- appropriate group), and he/she can create
- subgroups as well as add processes to
- the group.</p></dd><dt id="ControlGroupPersistent="><span class="term"><code class="varname">ControlGroupPersistent=</code></span><a class="headerlink" title="Permalink to this term" href="#ControlGroupPersistent=">¶</a></dt><dd><p>Takes a boolean
- argument. If true, the control groups
- created for this unit will be marked
- to be persistent, i.e. systemd will
- not remove them when stopping the
- unit. The default is false, meaning
- that the control groups will be
- removed when the unit is stopped. For
- details about the semantics of this
- logic see <a class="ulink" href="http://www.freedesktop.org/wiki/Software/systemd/PaxControlGroups" target="_top">PaxControlGroups</a>.</p></dd><dt id="ControlGroupAttribute="><span class="term"><code class="varname">ControlGroupAttribute=</code></span><a class="headerlink" title="Permalink to this term" href="#ControlGroupAttribute=">¶</a></dt><dd><p>Set a specific control
- group attribute for executed
- processes, and (if needed) add the
- executed processes to a cgroup in the
- hierarchy of the controller the
- attribute belongs to. Takes two
- space-separated arguments: the
- attribute name (syntax is
- <code class="literal">cpu.shares</code> where
- <code class="literal">cpu</code> refers to a
- specific controller and
- <code class="literal">shares</code> to the
- attribute name), and the attribute
- value. Example:
- <code class="literal">ControlGroupAttribute=cpu.shares
- 512</code>. If this option is used
- for an attribute that belongs to a
- kernel controller hierarchy the unit
- is not already configured to be added
- to (for example via the
- <code class="literal">ControlGroup=</code>
- option) then the unit will be added to
- the controller and the default unit
- cgroup path is implied. Thus, using
- <code class="varname">ControlGroupAttribute=</code>
- is in most cases sufficient to make
- use of control group enforcements,
- explicit
- <code class="varname">ControlGroup=</code> are
- only necessary in case the implied
- default control group path for a
- service is not desirable. For details
- about control group attributes see
- <a class="ulink" href="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt" target="_top">cgroups.txt</a>. This
- option may appear more than once, in
- order to set multiple control group
- attributes. If this option is used
- multiple times for the same cgroup
- attribute only the later setting takes
- effect. If the empty string is
- assigned to this option the list of
- attributes is reset, all previous
- cgroup attribute settings have no
- effect, including those done with
- <code class="varname">CPUShares=</code>,
- <code class="varname">MemoryLimit=</code>,
- <code class="varname">MemorySoftLimit</code>,
- <code class="varname">DeviceAllow=</code>,
- <code class="varname">DeviceDeny=</code>,
- <code class="varname">BlockIOWeight=</code>,
- <code class="varname">BlockIOReadBandwidth=</code>,
- <code class="varname">BlockIOWriteBandwidth=</code>.
- </p></dd><dt id="CPUShares="><span class="term"><code class="varname">CPUShares=</code></span><a class="headerlink" title="Permalink to this term" href="#CPUShares=">¶</a></dt><dd><p>Assign the specified
- overall CPU time shares to the
- processes executed. Takes an integer
- value. This controls the
- <code class="literal">cpu.shares</code> control
- group attribute, which defaults to
- 1024. For details about this control
- group attribute see <a class="ulink" href="http://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt" target="_top">sched-design-CFS.txt</a>.</p></dd><dt id="MemoryLimit="><span class="term"><code class="varname">MemoryLimit=</code>, </span><span class="term"><code class="varname">MemorySoftLimit=</code></span><a class="headerlink" title="Permalink to this term" href="#MemoryLimit=">¶</a></dt><dd><p>Limit the overall memory usage
- of the executed processes to a certain
- size. Takes a memory size in bytes. If
- the value is suffixed with K, M, G or
- T the specified memory size is parsed
- as Kilobytes, Megabytes, Gigabytes,
- or Terabytes (to the base
- 1024), respectively. This controls the
- <code class="literal">memory.limit_in_bytes</code>
- and
- <code class="literal">memory.soft_limit_in_bytes</code>
- control group attributes. For details
- about these control group attributes
- see <a class="ulink" href="http://www.kernel.org/doc/Documentation/cgroups/memory.txt" target="_top">memory.txt</a>.</p></dd><dt id="DeviceAllow="><span class="term"><code class="varname">DeviceAllow=</code>, </span><span class="term"><code class="varname">DeviceDeny=</code></span><a class="headerlink" title="Permalink to this term" href="#DeviceAllow=">¶</a></dt><dd><p>Control access to
- specific device nodes by the executed processes. Takes two
- space separated strings: a device node
- path (such as
- <code class="filename">/dev/null</code>)
- followed by a combination of r, w, m
- to control reading, writing, or
- creating of the specific device node
- by the unit, respectively. This controls the
- <code class="literal">devices.allow</code>
- and
- <code class="literal">devices.deny</code>
- control group attributes. For details
- about these control group attributes
- see <a class="ulink" href="http://www.kernel.org/doc/Documentation/cgroups/devices.txt" target="_top">devices.txt</a>.</p></dd><dt id="BlockIOWeight="><span class="term"><code class="varname">BlockIOWeight=</code></span><a class="headerlink" title="Permalink to this term" href="#BlockIOWeight=">¶</a></dt><dd><p>Set the default or
- per-device overall block IO weight
- value for the executed
- processes. Takes either a single
- weight value (between 10 and 1000) to
- set the default block IO weight, or a
- space separated pair of a file path
- and a weight value to specify the
- device specific weight value (Example:
- "/dev/sda 500"). The file path may be
- specified as path to a block device
- node or as any other file in which
- case the backing block device of the
- file system of the file is
- determined. This controls the
- <code class="literal">blkio.weight</code> and
- <code class="literal">blkio.weight_device</code>
- control group attributes, which
- default to 1000. Use this option
- multiple times to set weights for
- multiple devices. For details about
- these control group attributes see
- <a class="ulink" href="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt" target="_top">blkio-controller.txt</a>.</p></dd><dt id="BlockIOReadBandwidth="><span class="term"><code class="varname">BlockIOReadBandwidth=</code>, </span><span class="term"><code class="varname">BlockIOWriteBandwidth=</code></span><a class="headerlink" title="Permalink to this term" href="#BlockIOReadBandwidth=">¶</a></dt><dd><p>Set the per-device
- overall block IO bandwidth limit for
- the executed processes. Takes a space
- separated pair of a file path and a
- bandwidth value (in bytes per second)
- to specify the device specific
- bandwidth. The file path may be
- specified as path to a block device
- node or as any other file in which
- case the backing block device of the
- file system of the file is determined.
- If the bandwidth is suffixed with K, M,
- G, or T the specified bandwidth is
- parsed as Kilobytes, Megabytes,
- Gigabytes, or Terabytes, respectively (Example:
- "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0
- 5M"). This controls the
- <code class="literal">blkio.read_bps_device</code>
- and
- <code class="literal">blkio.write_bps_device</code>
- control group attributes. Use this
- option multiple times to set bandwidth
- limits for multiple devices. For
- details about these control group
- attributes see <a class="ulink" href="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt" target="_top">blkio-controller.txt</a>.</p></dd><dt id="ReadWriteDirectories="><span class="term"><code class="varname">ReadWriteDirectories=</code>, </span><span class="term"><code class="varname">ReadOnlyDirectories=</code>, </span><span class="term"><code class="varname">InaccessibleDirectories=</code></span><a class="headerlink" title="Permalink to this term" href="#ReadWriteDirectories=">¶</a></dt><dd><p>Sets up a new
- file-system name space for executed
+ setting.</p></dd><dt id="ReadWriteDirectories="><span class="term"><code class="varname">ReadWriteDirectories=</code>, </span><span class="term"><code class="varname">ReadOnlyDirectories=</code>, </span><span class="term"><code class="varname">InaccessibleDirectories=</code></span><a class="headerlink" title="Permalink to this term" href="#ReadWriteDirectories=">¶</a></dt><dd><p>Sets up a new
+ file system namespace for executed
processes. These options may be used
to limit access a process might have
- to the main file-system
+ to the main file system
hierarchy. Each setting takes a
space-separated list of absolute
directory paths. Directories listed in
directories listed will have limited
access from within the namespace. If
the empty string is assigned to this
- option the specific list is reset, and
+ option, the specific list is reset, and
all prior assignments have no
- effect.</p></dd><dt id="PrivateTmp="><span class="term"><code class="varname">PrivateTmp=</code></span><a class="headerlink" title="Permalink to this term" href="#PrivateTmp=">¶</a></dt><dd><p>Takes a boolean
- argument. If true sets up a new file
+ effect.</p><p>Paths in
+ <code class="varname">ReadOnlyDirectories=</code>
+ and
+ <code class="varname">InaccessibleDirectories=</code>
+ may be prefixed with
+ "<code class="literal">-</code>", in which case
+ they will be ignored when they do not
+ exist.</p></dd><dt id="PrivateTmp="><span class="term"><code class="varname">PrivateTmp=</code></span><a class="headerlink" title="Permalink to this term" href="#PrivateTmp=">¶</a></dt><dd><p>Takes a boolean
+ argument. If true, sets up a new file
system namespace for the executed
processes and mounts private
<code class="filename">/tmp</code> and
by service will be removed after service
is stopped. Defaults to
false.</p></dd><dt id="PrivateNetwork="><span class="term"><code class="varname">PrivateNetwork=</code></span><a class="headerlink" title="Permalink to this term" href="#PrivateNetwork=">¶</a></dt><dd><p>Takes a boolean
- argument. If true sets up a new
+ argument. If true, sets up a new
network namespace for the executed
processes and configures only the
loopback network device
- <code class="literal">lo</code> inside it. No
+ "<code class="literal">lo</code>" inside it. No
other network devices will be
available to the executed process.
This is useful to securely turn off
entries must be created and cleared
before and after execution. If the
configured string is longer than four
- characters it is truncated and the
+ characters, it is truncated and the
terminal four characters are
used. This setting interprets %I style
string replacements. This setting is
unset by default, i.e. no utmp/wtmp
entries are created or cleaned up for
this service.</p></dd><dt id="IgnoreSIGPIPE="><span class="term"><code class="varname">IgnoreSIGPIPE=</code></span><a class="headerlink" title="Permalink to this term" href="#IgnoreSIGPIPE=">¶</a></dt><dd><p>Takes a boolean
- argument. If true causes SIGPIPE to be
+ argument. If true, causes <code class="constant">SIGPIPE</code> to be
ignored in the executed
- process. Defaults to true, since
- SIGPIPE generally is useful only in
+ process. Defaults to true because
+ <code class="constant">SIGPIPE</code> generally is useful only in
shell pipelines.</p></dd><dt id="NoNewPrivileges="><span class="term"><code class="varname">NoNewPrivileges=</code></span><a class="headerlink" title="Permalink to this term" href="#NoNewPrivileges=">¶</a></dt><dd><p>Takes a boolean
- argument. If true ensures that the
+ argument. If true, ensures that the
service process and all its children
can never gain new privileges. This
option is more powerful than the respective
kind. This is the simplest, most
effective way to ensure that a process
and its children can never elevate
- privileges again.</p></dd><dt id="SystemCallFilter="><span class="term"><code class="varname">SystemCallFilter=</code></span><a class="headerlink" title="Permalink to this term" href="#SystemCallFilter=">¶</a></dt><dd><p>Takes a space
- separated list of system call
- names. If this setting is used all
+ privileges again.</p></dd><dt id="SystemCallFilter="><span class="term"><code class="varname">SystemCallFilter=</code></span><a class="headerlink" title="Permalink to this term" href="#SystemCallFilter=">¶</a></dt><dd><p>Takes a space-separated
+ list of system call
+ names. If this setting is used, all
system calls executed by the unit
process except for the listed ones
will result in immediate process
- termination with the SIGSYS signal
+ termination with the
+ <code class="constant">SIGSYS</code> signal
(whitelisting). If the first character
- of the list is <code class="literal">~</code>
+ of the list is "<code class="literal">~</code>",
the effect is inverted: only the
listed system calls will result in
immediate process termination
- (blacklisting). If this option is used
+ (blacklisting). If this option is used,
<code class="varname">NoNewPrivileges=yes</code>
is implied. This feature makes use of
the Secure Computing Mode 2 interfaces
<code class="function">sigreturn</code>,
<code class="function">exit_group</code>,
<code class="function">exit</code> system calls
- are implicitly whitelisted and don't
+ are implicitly whitelisted and do not
need to be listed explicitly. This
option may be specified more than once
in which case the filter masks are
merged. If the empty string is
- assigned the filter is reset, all
+ assigned, the filter is reset, all
prior assignments will have no
- effect.</p></dd></dl></div></div><div class="refsect1"><a name="idm259785902736"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
+ effect.</p></dd></dl></div></div><div class="refsect1"><a name="idm274701565696"></a><h2 id="Environment variables in spawned processes">Environment variables in spawned processes<a class="headerlink" title="Permalink to this headline" href="#Environment%20variables%20in%20spawned%20processes">¶</a></h2><p>Processes started by the system are executed in
+ a clean environment in which select variables
+ listed below are set. System processes started by systemd
+ do not inherit variables from PID 1, but processes
+ started by user systemd instances inherit all
+ environment variables from the user systemd instance.
+ </p><div class="variablelist"><dl class="variablelist"><dt id="$PATH"><span class="term"><code class="varname">$PATH</code></span><a class="headerlink" title="Permalink to this term" href="#%24PATH">¶</a></dt><dd><p>Colon-separated list
+ of directiories to use when launching
+ executables. Systemd uses a fixed
+ value of
+ <code class="filename">/usr/local/sbin</code>:<code class="filename">/usr/local/bin</code>:<code class="filename">/usr/sbin</code>:<code class="filename">/usr/bin</code>:<code class="filename">/sbin</code>:<code class="filename">/bin</code>.
+ </p></dd><dt id="$LANG"><span class="term"><code class="varname">$LANG</code></span><a class="headerlink" title="Permalink to this term" href="#%24LANG">¶</a></dt><dd><p>Locale. Can be set in
+ <a href="locale.conf.html"><span class="citerefentry"><span class="refentrytitle">locale.conf</span>(5)</span></a>
+ or on the kernel command line (see
+ <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>
+ and
+ <a href="kernel-command-line.html"><span class="citerefentry"><span class="refentrytitle">kernel-command-line</span>(7)</span></a>).
+ </p></dd><dt id="$USER"><span class="term"><code class="varname">$USER</code>, </span><span class="term"><code class="varname">$HOME</code></span><a class="headerlink" title="Permalink to this term" href="#%24USER">¶</a></dt><dd><p>User name and home
+ directory. Set for the units which
+ have <code class="varname">User=</code> set,
+ which includes user
+ <span class="command"><strong>systemd</strong></span> instances.
+ See
+ <a href="passwd.html"><span class="citerefentry"><span class="refentrytitle">passwd</span>(5)</span></a>.
+ </p></dd><dt id="$XDG_RUNTIME_DIR"><span class="term"><code class="varname">$XDG_RUNTIME_DIR</code></span><a class="headerlink" title="Permalink to this term" href="#%24XDG_RUNTIME_DIR">¶</a></dt><dd><p>The directory for volatile
+ state. Set for the user <span class="command"><strong>systemd</strong></span>
+ instance, and also in user sessions.
+ See
+ <a href="pam_systemd.html"><span class="citerefentry"><span class="refentrytitle">pam_systemd</span>(8)</span></a>.
+ </p></dd><dt id="$XDG_SESSION_ID"><span class="term"><code class="varname">$XDG_SESSION_ID</code>, </span><span class="term"><code class="varname">$XDG_SEAT</code>, </span><span class="term"><code class="varname">$XDG_VTNR</code></span><a class="headerlink" title="Permalink to this term" href="#%24XDG_SESSION_ID">¶</a></dt><dd><p>The identifier of the
+ session, and the seat name, and
+ virtual terminal of the session. Set
+ by
+ <a href="pam_systemd.html"><span class="citerefentry"><span class="refentrytitle">pam_systemd</span>(8)</span></a>
+ for login sessions.
+ <code class="varname">$XDG_SEAT</code> and
+ <code class="varname">$XDG_VTNR</code> will be
+ only set when attached to a seat and a
+ tty.</p></dd><dt id="$MANAGERPID"><span class="term"><code class="varname">$MANAGERPID</code></span><a class="headerlink" title="Permalink to this term" href="#%24MANAGERPID">¶</a></dt><dd><p>The PID of the user
+ <span class="command"><strong>systemd</strong></span> instance,
+ set for processes spawned by it.
+ </p></dd><dt id="$LISTEN_FDS"><span class="term"><code class="varname">$LISTEN_FDS</code>, </span><span class="term"><code class="varname">$LISTEN_PID</code></span><a class="headerlink" title="Permalink to this term" href="#%24LISTEN_FDS">¶</a></dt><dd><p>Information about file
+ descriptors passed to a service for
+ socket activation. See
+ <a href="sd_listen_fds.html"><span class="citerefentry"><span class="refentrytitle">sd_listen_fds</span>(3)</span></a>.
+ </p></dd></dl></div><p>Additional variables may be configured by the
+ following means: for processes spawned in specific
+ units, use the <code class="varname">Environment=</code> and
+ <code class="varname">EnvironmentFile=</code> options above; to
+ specify variables globally, use
+ <code class="varname">DefaultEnvironment=</code> (see
+ <a href="systemd-system.conf.html"><span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span></a>)
+ or the kernel option
+ <code class="varname">systemd.setenv=</code> (see
+ <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>). Additional
+ variables may also be set through PAM,
+ c.f. <a href="pam_env.html"><span class="citerefentry"><span class="refentrytitle">pam_env</span>(8)</span></a>.</p></div><div class="refsect1"><a name="idm274701532960"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
<a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
<a href="systemctl.html"><span class="citerefentry"><span class="refentrytitle">systemctl</span>(8)</span></a>,
<a href="journalctl.html"><span class="citerefentry"><span class="refentrytitle">journalctl</span>(8)</span></a>,
<a href="systemd.swap.html"><span class="citerefentry"><span class="refentrytitle">systemd.swap</span>(5)</span></a>,
<a href="systemd.mount.html"><span class="citerefentry"><span class="refentrytitle">systemd.mount</span>(5)</span></a>,
<a href="systemd.kill.html"><span class="citerefentry"><span class="refentrytitle">systemd.kill</span>(5)</span></a>,
- <a href="systemd.directives.html"><span class="citerefentry"><span class="refentrytitle">systemd.directives</span>(7)</span></a>
+ <a href="systemd.resource-control.html"><span class="citerefentry"><span class="refentrytitle">systemd.resource-control</span>(5)</span></a>,
+ <a href="systemd.directives.html"><span class="citerefentry"><span class="refentrytitle">systemd.directives</span>(7)</span></a>,
+ <a href="exec.html"><span class="citerefentry"><span class="refentrytitle">exec</span>(3)</span></a>
</p></div></div></body></html>
projects / systemd.git / blobdiff