tmpfiles.d — Configuration for creation, deletion and cleaning of volatile and temporary files
/etc/tmpfiles.d/*.conf
/run/tmpfiles.d/*.conf
/usr/lib/tmpfiles.d/*.conf
systemd-tmpfiles uses the
configuration files from the above directories to describe the
creation, cleaning and removal of volatile and
temporary files and directories which usually reside
in directories such as /run
or /tmp.
Volatile and temporary files and directories are
those located in /run (and its
alias /var/run),
/tmp,
/var/tmp, the API file systems
such as /sys or
/proc, as well as some other
directories below /var.
System daemons frequently require private
runtime directories below /run to
place communication sockets and similar in. For these,
consider declaring them in their unit files using
RuntimeDirectory=
(see systemd.exec(5) for details),
if this is feasible.
Each configuration file shall be named in the
style of
package.confpackage-part.conf
Files in /etc/tmpfiles.d
override files with the same name in
/usr/lib/tmpfiles.d and
/run/tmpfiles.d. Files in
/run/tmpfiles.d override files
with the same name in
/usr/lib/tmpfiles.d. Packages
should install their configuration files in
/usr/lib/tmpfiles.d. Files in
/etc/tmpfiles.d are reserved for
the local administrator, who may use this logic to
override the configuration files installed by vendor
packages. All configuration files are sorted by their
filename in lexicographic order, regardless of which
of the directories they reside in. If multiple files
specify the same path, the entry in the file with the
lexicographically earliest name will be applied, all
all other conflicting entries will be logged as
errors. When two lines are prefix and suffix of each
other, then the prefix is always processed first, the
suffix later. Otherwise, the files/directories are
processed in the order they are listed.
If the administrator wants to disable a
configuration file supplied by the vendor, the
recommended way is to place a symlink to
/dev/null in
/etc/tmpfiles.d/ bearing the
same filename.
The configuration format is one line per path containing type, path, mode, ownership, age, and argument fields:
#Type Path Mode UID GID Age Argument d /run/user 0755 root root 10d - L /tmp/foobar - - - - /dev/null
The type consists of a single letter and optionally an exclamation mark.
The following line types are understood:
f¶Create a file if it does not exist yet. If the argument parameter is given, it will be written to the file.
F¶Create or truncate a file. If the argument parameter is given, it will be written to the file.
w¶Write the argument parameter to a file, if the file exists. Lines of this type accept shell-style globs in place of normal path names. The argument parameter will be written without a trailing newline. C-style backslash escapes are interpreted.
d¶Create a directory if it does not exist yet.
D¶Create or empty a directory.
p, p+¶Create a named
pipe (FIFO) if it does not
exist yet. If suffixed with
+ and a
file already exists where the
pipe is to be created, it will
be removed and be replaced by
the pipe.
L, L+¶Create a
symlink if it does not exist
yet. If suffixed with
+ and a
file already exists where the
symlink is to be created, it
will be removed and be
replaced by the
symlink. If the argument is omitted,
symlinks to files with the same name
residing in the directory
/usr/share/factory/
are created.
c, c+¶Create a
character device node if it
does not exist yet. If
suffixed with
+ and a
file already exists where the
device node is to be created,
it will be removed and be
replaced by the device
node. It is recommended to suffix this
entry with an exclamation mark to only
create static device nodes at boot,
as udev will not manage static device
nodes that are created at runtime.
b, b+¶Create a block
device node if it does not
exist yet. If suffixed with
+ and a
file already exists where the
device node is to be created,
it will be removed and be
replaced by the device
node. It is recommended to suffix this
entry with an exclamation mark to only
create static device nodes at boot,
as udev will not manage static device
nodes that are created at runtime.
C¶Recursively
copy a file or directory, if
the destination files or
directories do not exist
yet. Note that this command
will not descend into
subdirectories if the
destination directory already
exists. Instead, the entire
copy operation is
skipped. If the argument is omitted,
files from the source directory
/usr/share/factory/
with the same name are copied.
x¶Ignore a path
during cleaning. Use this type
to exclude paths from clean-up
as controlled with the Age
parameter. Note that lines of
this type do not influence the
effect of r
or R lines.
Lines of this type accept
shell-style globs in place of
normal path names.
X¶Ignore a path
during cleaning. Use this type
to exclude paths from clean-up
as controlled with the Age
parameter. Unlike
x, this
parameter will not exclude the
content if path is a
directory, but only directory
itself. Note that lines of
this type do not influence the
effect of r
or R lines.
Lines of this type accept
shell-style globs in place of
normal path names.
r¶Remove a file
or directory if it exists.
This may not be used to remove
non-empty directories, use
R for that.
Lines of this type accept
shell-style globs in place of
normal path
names.
R¶Recursively remove a path and all its subdirectories (if it is a directory). Lines of this type accept shell-style globs in place of normal path names.
z¶Adjust the access mode, group and user, and restore the SELinux security context of a file or directory, if it exists. Lines of this type accept shell-style globs in place of normal path names.
Z¶Recursively set the access mode, group and user, and restore the SELinux security context of a file or directory if it exists, as well as of its subdirectories and the files contained therein (if applicable). Lines of this type accept shell-style globs in place of normal path names.
If the exclamation mark is used, this
line is only safe of execute during boot, and
can break a running system. Lines without the
exclamation mark are presumed to be safe to
execute at any time, e.g. on package upgrades.
systemd-tmpfiles will
execute line with an exclamation mark only if
option --boot is given.
For example:
# Make sure these are created by default so that nobody else can d /tmp/.X11-unix 1777 root root 10d # Unlink the X11 lock files r! /tmp/.X[0-9]*-lock
The second line in contrast to the first one
would break a running system, and will only be
executed with --boot.
The file system path specification supports simple specifier expansion. The following expansions are understood:
Table 1. Specifiers available
| Specifier | Meaning | Details |
|---|---|---|
"%m" | Machine ID | The machine ID of the running system, formatted as string. See machine-id(5) for more information. |
"%b" | Boot ID | The boot ID of the running system, formatted as string. See random(4) for more information. |
"%H" | Host name | The hostname of the running system. |
"%v" | Kernel release | Identical to uname -r output. |
"%%" | Escaped % | Single percent sign. |
The file access mode to use when
creating this file or directory. If omitted or
when set to -, the default is used: 0755 for
directories, 0644 for all other file objects.
For z, Z
lines, if omitted or when set to
"-", the file access mode
will not be modified. This parameter is
ignored for x,
r, R,
L lines.
Optionally, if prefixed with
"~", the access mode is masked
based on the already set access bits for
existing file or directories: if the existing
file has all executable bits unset, all
executable bits are removed from the new
access mode, too. Similarly, if all read bits
are removed from the old access mode, they will
be removed from the new access mode too, and
if all write bits are removed, they will be
removed from the new access mode too. In
addition, the sticky/SUID/SGID bit is removed unless
applied to a directory. This
functionality is particularly useful in
conjunction with Z.
The user and group to use for this file
or directory. This may either be a numeric
user/group ID or a user or group name. If
omitted or when set to "-",
the default 0 (root) is used. For
z, Z
lines, when omitted or when set to -, the file
ownership will not be modified. These
parameters are ignored for
x, r,
R, L
lines.
The date field, when set, is used to decide what files to delete when cleaning. If a file or directory is older than the current time minus the age field, it is deleted. The field format is a series of integers each followed by one of the following postfixes for the respective time units:
s, min, h, d, w, ms, m, us¶If multiple integers and units are specified, the time values are summed up. If an integer is given without a unit, s is assumed.
When the age is set to zero, the files are cleaned unconditionally.
The age field only applies to lines
starting with d,
D, and
x. If omitted or set to
"-", no automatic clean-up is
done.
If the age field starts with a tilde
character "~", the clean-up
is only applied to files and directories one
level inside the directory specified, but not
the files and directories immediately inside
it.
For L lines
determines the destination path of the
symlink. For c,
b determines the
major/minor of the device node, with major and
minor formatted as integers, separated by
":", e.g.
"1:3". For
f, F,
and w may be used to
specify a short string that is written to the
file, suffixed by a newline. For
C, specifies the source file
or directory. Ignored for all other
lines.
Example 1. /etc/tmpfiles.d/screen.conf example
screen needs two directories created at boot with specific modes and ownership.
d /run/screens 1777 root root 10d d /run/uscreens 0755 root root 10d12h
Example 2. /etc/tmpfiles.d/abrt.conf example
abrt needs a directory created at boot with specific mode and ownership and its content should be preserved.
d /var/tmp/abrt 0755 abrt abrt x /var/tmp/abrt/*