tmpfiles.d
systemd
Documentation
Brandon
Philips
brandon@ifup.org
tmpfiles.d
5
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
Description
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.
Configuration Format
Each configuration file shall be named in the
style of <package>.conf.
Files in /etc/ override files
with the same name in /usr/lib/
and /run/. Files in
/run/ override files with the same
name in /usr/lib/. Packages
should install their configuration files in
/usr/lib/. Files in
/etc/ 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 in which of the
directories they reside. 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 logged as errors.
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 action, 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
Type
The following line types are understood:
f
Create a file if it does not exist yet (optionally writing a short string into it, if the argument parameter is passed)
F
Create or truncate a file (optionally writing a short string into it, if the argument parameter is passed)
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
Create a named pipe (FIFO) if it does not exist yet
L
Create a symlink if it does not exist yet
c
Create a character device node if it does not exist yet
b
Create a block device node if it does not exist yet
m
If the
specified file path exists,
adjust its access mode, group
and user to the specified
values and reset the SELinux
label. If it does not exist, do
nothing.
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
Restore
SELinux security context label
and set ownership and access
mode of a file or directory if
it exists. Lines of this type
accept shell-style globs in
place of normal path names.
Z
Recursively
restore SELinux security
context label and set
ownership and access mode of 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.
Path
The file system path specification supports simple specifier
expansion. The following expansions are
understood:
Specifiers available
Specifier
Meaning
Details
%m
Machine ID
The machine ID of the running system, formatted as string. See machine-id5 for more information.
%b
Boot ID
The boot ID of the running system, formatted as string. See random4 for more information.
%H
Host name
The hostname of the running system.
%v
Kernel release
Identical to uname -r output.
%%
Escaped %
Single percent sign.
Mode
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.
UID, GID
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.
Age
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.
Argument
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, w may be used to specify
a short string that is written to the file,
suffixed by a newline. Ignored for all other
lines.
Example
/etc/tmpfiles.d/screen.conf example
screen needs two directories created at boot with specific modes and ownership.
d /var/run/screens 1777 root root 10d
d /var/run/uscreens 0755 root root 10d12h
/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/*
See Also
systemd1,
systemd-tmpfiles8,
systemd-delta1