TMPFILES.D(5) tmpfiles.d TMPFILES.D(5)
NAME
tmpfiles.d - Configuration for creation, deletion, and cleaning of files
and directories
SYNOPSIS
/etc/tmpfiles.d/*.conf
/run/tmpfiles.d/*.conf
/usr/local/lib/tmpfiles.d/*.conf
/usr/lib/tmpfiles.d/*.conf
~/.config/user-tmpfiles.d/*.conf
$XDG_RUNTIME_DIR/user-tmpfiles.d/*.conf
~/.local/share/user-tmpfiles.d/*.conf
...
/usr/local/share/user-tmpfiles.d/*.conf
/usr/share/user-tmpfiles.d/*.conf
#Type Path Mode User Group Age Argument
f /file/to/create mode user group - content
f+ /file/to/create-or-truncate mode user group - content
w /file/to/write-to - - - - content
w+ /file/to/append-to - - - - content
d /directory/to/create-and-clean-up mode user group cleanup-age -
D /directory/to/create-and-remove mode user group cleanup-age -
e /directory/to/clean-up mode user group cleanup-age -
v /subvolume-or-directory/to/create mode user group cleanup-age -
q /subvolume-or-directory/to/create mode user group cleanup-age -
Q /subvolume-or-directory/to/create mode user group cleanup-age -
p /fifo/to/create mode user group - -
p+ /fifo/to/[re]create mode user group - -
L /symlink/to/create - - - - symlink/target/path
L+ /symlink/to/[re]create - - - - symlink/target/path
c /dev/char-device-to-create mode user group - major:minor
c+ /dev/char-device-to-[re]create mode user group - major:minor
b /dev/block-device-to-create mode user group - major:minor
b+ /dev/block-device-to-[re]create mode user group - major:minor
C /target/to/create - - - cleanup-age /source/to/copy
C+ /target/to/create - - - cleanup-age /source/to/copy
x /path-or-glob/to/ignore/recursively - - - cleanup-age -
X /path-or-glob/to/ignore - - - cleanup-age -
r /path-or-glob/to/remove - - - - -
R /path-or-glob/to/remove/recursively - - - - -
z /path-or-glob/to/adjust/mode mode user group - -
Z /path-or-glob/to/adjust/mode/recursively mode user group - -
t /path-or-glob/to/set/xattrs - - - - xattrs
T /path-or-glob/to/set/xattrs/recursively - - - - xattrs
h /path-or-glob/to/set/attrs - - - - file attrs
H /path-or-glob/to/set/attrs/recursively - - - - file attrs
a /path-or-glob/to/set/acls - - - - POSIX ACLs
a+ /path-or-glob/to/append/acls - - - - POSIX ACLs
A /path-or-glob/to/set/acls/recursively - - - - POSIX ACLs
A+ /path-or-glob/to/append/acls/recursively - - - - POSIX ACLs
DESCRIPTION
tmpfiles.d configuration files provide a generic mechanism to define the
creation of regular files, directories, pipes, and device nodes,
adjustments to their access mode, ownership, attributes, quota
assignments, and contents, and finally their time-based removal. It is
mostly commonly used for volatile and temporary files and directories
(such as those located under /run/, /tmp/, /var/tmp/, the API file
systems such as /sys/ or /proc/, as well as some other directories below
/var/).
systemd-tmpfiles(8) uses this configuration to create volatile files and
directories during boot and to do periodic cleanup afterwards. See
systemd-tmpfiles(8) for the description of
systemd-tmpfiles-setup.service, systemd-tmpfiles-clean.service, and
associated units.
System daemons frequently require private runtime directories below
/run/ to store communication sockets and similar. For these, it is
better to use RuntimeDirectory= in their unit files (see systemd.exec(5)
for details), if the flexibility provided by tmpfiles.d is not required.
The advantages are that the configuration required by the unit is
centralized in one place, and that the lifetime of the directory is tied
to the lifetime of the service itself. Similarly, StateDirectory=,
CacheDirectory=, LogsDirectory=, and ConfigurationDirectory= should be
used to create directories under /var/lib/, /var/cache/, /var/log/, and
/etc/. tmpfiles.d should be used for files whose lifetime is
independent of any service or requires more complicated configuration.
CONFIGURATION DIRECTORIES AND PRECEDENCE
Each configuration file shall be named in the style of package.conf or
package-part.conf. The second variant should be used when it is
desirable to make it easy to override just this part of configuration.
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 (note that lines
suppressed due to the "!" are filtered before application, meaning that
if an early line carries the exclamation mark and is suppressed because
of that, a later line matching in path will be applied). All other
conflicting entries will be logged as errors. When two lines are prefix
path and suffix path of each other, then the prefix line is always
created first, the suffix later (and if removal applies to the line, the
order is reversed: the suffix is removed first, the prefix later). Lines
that take globs are applied after those accepting no globs. If multiple
operations shall be applied on the same file (such as ACL, xattr, file
attribute adjustments), these are always done in the same fixed order.
Except for those cases, 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.
CONFIGURATION FILE FORMAT
The configuration format is one line per path, containing type, path,
mode, ownership, age, and argument fields. The lines are separated by
newlines, the fields by whitespace:
#Type Path Mode User Group Age Argument...
d /run/user 0755 root root 10d -
L /tmp/foobar - - - - /dev/null
Fields may contain C-style escapes. With the exception of the seventh
field (the "argument") all fields may be enclosed in quotes. Note that
any whitespace found in the line after the beginning of the argument
field will be considered part of the argument field. To begin the
argument field with a whitespace character, use C-style escapes (e.g.
"\x20").
Type
The type consists of a single letter and optionally one or more modifier
characters: a plus sign ("+"), exclamation mark ("!"), minus sign ("-"),
equals sign ("="), tilde character ("~") and/or caret ("^").
The following line types are understood:
f, f+
f will create a file if it does not exist yet. If the argument
parameter is given and the file did not exist yet, it will be
written to the file. f+ will create or truncate the file. If the
argument parameter is given, it will be written to the file. Does
not follow symlinks.
w, w+
Write the argument parameter to a file, if the file exists. If
suffixed with +, the line will be appended to the file. If your
configuration writes multiple lines to the same file, use w+. 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. Follows symlinks.
d
Create a directory. The mode and ownership will be adjusted if
specified. Contents of this directory are subject to time-based
cleanup if the age argument is specified.
D
Similar to d, but in addition the contents of the directory will be
removed when --remove is used.
e
Adjust the mode and ownership of existing directories and remove
their contents based on age. Lines of this type accept shell-style
globs in place of normal path names. Contents of the directories are
subject to time-based cleanup if the age argument is specified. If
the age argument is "0", contents will be unconditionally deleted
every time systemd-tmpfiles(8) --clean is run.
For this entry to be useful, at least one of the mode, user, group,
or age arguments must be specified, since otherwise this entry has
no effect. As an exception, an entry with no effect may be useful
when combined with !, see the examples.
Added in version 230.
v
Create a subvolume if the path does not exist yet, the file system
supports subvolumes (btrfs), and the system itself is installed into
a subvolume (specifically: the root directory / is itself a
subvolume). Otherwise, create a normal directory, in the same way as
d.
A subvolume created with this line type is not assigned to any
higher-level quota group. For that, use q or Q, which allow creating
simple quota group hierarchies, see below.
Added in version 219.
q
Create a subvolume or directory the same as v, but assign the
subvolume to the same higher-level quota groups as the parent. This
ensures that higher-level limits and accounting applied to the
parent subvolume also include the specified subvolume. On non-btrfs
file systems, this line type is identical to d.
If the subvolume already exists, no change to the quota hierarchy is
made, regardless of whether the subvolume is already attached to a
quota group or not. Also see Q below. See btrfs-qgroup(8) for
details about the btrfs quota group concept.
Added in version 228.
Q
Create the subvolume or directory the same as v, but assign the new
subvolume to a new leaf quota group. Instead of copying the
higher-level quota group assignments from the parent as is done with
q, the lowest quota group of the parent subvolume is determined that
is not the leaf quota group. Then, an "intermediary" quota group is
inserted that is one level below this level, and shares the same ID
part as the specified subvolume. If no higher-level quota group
exists for the parent subvolume, a new quota group at level 255
sharing the same ID as the specified subvolume is inserted instead.
This new intermediary quota group is then assigned to the parent
subvolume's higher-level quota groups, and the specified subvolume's
leaf quota group is assigned to it.
Effectively, this has a similar effect as q, however introduces a
new higher-level quota group for the specified subvolume that may be
used to enforce limits and accounting to the specified subvolume and
children subvolume created within it. Thus, by creating subvolumes
only via q and Q, a concept of "subtree quotas" is implemented. Each
subvolume for which Q is set will get a "subtree" quota group
created, and all child subvolumes created within it will be assigned
to it. Each subvolume for which q is set will not get such a
"subtree" quota group, but it is ensured that they are added to the
same "subtree" quota group as their immediate parents.
It is recommended to use Q for subvolumes that typically contain
further subvolumes, and where it is desirable to have accounting and
quota limits on all child subvolumes together. Examples for Q are
typically /home/ or /var/lib/machines/. In contrast, q should be
used for subvolumes that either usually do not include further
subvolumes or where no accounting and quota limits are needed that
apply to all child subvolumes together. Examples for q are typically
/var/ or /var/tmp/.
As with q, Q has no effect on the quota group hierarchy if the
subvolume already exists, regardless of whether the subvolume
already belong to a quota group or not.
Added in version 228.
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+, L?
Create a symlink if it does not exist yet. If suffixed with + and a
file or directory already exists where the symlink is to be created,
it will be removed and be replaced by the symlink. If suffixed with
? and the source path does not exist, the symlink is not created.
If the argument is omitted, symlinks to files with the same name
residing in the directory /usr/share/factory/ are created. Note that
permissions on symlinks are ignored.
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, C+
Recursively copy a file or directory, if the destination files or
directories do not exist yet or the destination directory is empty.
Note that this command will not descend into subdirectories if the
destination directory already exists and is not empty, unless the
action is suffixed with +. 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. Does not follow
symlinks. Contents of the directories are subject to time-based
cleanup if the age argument is specified.
Added in version 214.
x
Ignore a path during cleaning. Use this type to exclude paths from
clean-up as controlled with the Age parameter. 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. Lines of this type accept shell-style globs
in place of normal path names.
Added in version 198.
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. Does not
follow symlinks.
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. Does not follow symlinks.
z
Adjust the access mode, user and group ownership, 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.
Does not follow symlinks.
Z
Recursively set the access mode, user and group ownership, 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. Does not follow symlinks.
t
Set extended attributes, see attr(5) for details. The argument field
should take one or more assignment expressions in the form
namespace.attribute=value, for examples see below. Lines of this
type accept shell-style globs in place of normal path names. This
can be useful for setting SMACK labels. Does not follow symlinks.
Please note that extended attributes settable with this line type
are a different concept from the Linux file attributes settable with
h/H, see below.
Added in version 218.
T
Same as t, but operates recursively.
Added in version 219.
h
Set Linux file/directory attributes. Lines of this type accept
shell-style globs in place of normal path names.
The format of the argument field is [+-=][aAcCdDeijPsStTu]. The
prefix + (the default one) causes the attributes to be added; -
causes the attributes to be removed; = causes the attributes to be
set exactly as the following letters. The letters "aAcCdDeijPsStTu"
select the new attributes for the files, see chattr(1) for further
information.
Passing only = as argument resets all the file attributes listed
above. It has to be pointed out that the = prefix limits itself to
the attributes corresponding to the letters listed here. All other
attributes will be left untouched. Does not follow symlinks.
Please note that the Linux file attributes settable with this line
type are a different concept from the extended attributes settable
with t/T, see above.
H
Sames as h, but operates recursively.
Added in version 220.
a, a+
Set POSIX ACLs (access control lists), see acl(5). Additionally, if
'X' is used, the execute bit is set only if the file is a directory
or already has execute permission for some user, as mentioned in
setfacl(1). If suffixed with +, the specified entries will be added
to the existing set. systemd-tmpfiles(8) will automatically add the
required base entries for user and group based on the access mode of
the file, unless base entries already exist or are explicitly
specified. The mask will be added if not specified explicitly or
already present. Lines of this type accept shell-style globs in
place of normal path names. This can be useful for allowing
additional access to certain files. Does not follow symlinks.
Added in version 219.
A, A+
Same as a and a+, but recursive. Does not follow symlinks.
Added in version 219.
Type Modifiers
If the exclamation mark ("!") is used, this line is only safe to 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(8) will take lines with an
exclamation mark only into consideration, if the --boot option 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.
If the minus sign ("-") is used, this line failing to run successfully
during create (and only create) will not cause the execution of systemd-
tmpfiles(8) to return an error.
For example:
# Modify sysfs but do not fail if we are in a container with a read-only /proc
w- /proc/sys/vm/swappiness - - - - 10
If the equals sign ("=") is used, the file types of existing objects in
the specified path are checked, and removed if they do not match. This
includes any implicitly created parent directories (which can be either
directories or directory symlinks). For example, if there is a FIFO in
place of one of the parent path components it will be replaced with a
directory.
If the tilde character ("~") is used, the argument (i.e. 6th) column is
Base64 decoded[1] before use. This modifier is only supported on line
types that can write file contents, i.e. f, f+, w, +. This is useful
for writing arbitrary binary data (including newlines and NUL bytes) to
files. Note that if this switch is used, the argument is not subject to
specifier expansion, neither before nor after Base64 decoding.
If the caret character ("^") is used, the argument (i.e. 6th) column
takes a service credential name to read the argument data from. See
System and Service Credentials[2] for details about the credentials
concept. This modifier is only supported on line types that can write
file contents, i.e. f, f+, w, w+. This is useful for writing arbitrary
files with contents sourced from elsewhere, including from VM or
container managers further up. If the specified credential is not set
for the systemd-tmpfiles service, the line is silently skipped. If "^"
and "~" are combined Base64 decoding is applied to the credential
contents.
If the dollar sign ("$") is used, the file becomes subject to removal
when systemd-tmpfiles is invoked with the --purge switch. Lines without
this character are unaffected by that switch.
Note that for all line types that result in creation of any kind of file
node (i.e. f, d/D/v/q/Q, p, L, c/b and C) leading directories are
implicitly created if needed, owned by root with an access mode of 0755.
In order to create them with different modes or ownership make sure to
add appropriate d lines.
Path
The file system path specification supports simple specifier expansion,
see below. The path (after expansion) must be absolute.
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, t, and a 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.
By default the access mode of listed inodes is set to the specified mode
regardless if it is created anew, or already existed. Optionally, if
prefixed with ":", the configured access mode is only applied when
creating new inodes, and if the inode the line refers to already exists,
its access mode is left in place unmodified.
User, Group
The user and group to use for this file or directory. This may either be
a numeric ID or a user/group name. If omitted or when set to "-", the
user and group of the user who invokes systemd-tmpfiles(8) is used. For
z and Z lines, when omitted or when set to "-", the file ownership will
not be modified. These parameters are ignored for x, r, R, t, and a
lines.
This field should generally only reference system users/groups, i.e.
users/groups that are guaranteed to be resolvable during early boot. If
this field references users/groups that only become resolveable during
later boot (i.e. after NIS, LDAP or a similar networked directory
service become available), execution of the operations declared by the
line will likely fail. Also see Notes on Resolvability of User and Group
Names[3] for more information on requirements on system user/group
definitions.
By default the ownership of listed inodes is set to the specified
user/group regardless if it is created anew, or already existed.
Optionally, if prefixed with ":", the configured user/group information
is only applied when creating new inodes, and if the inode the line
refers to already exists, its user/group is left in place unmodified.
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 suffixes for the respective time
units: s, m or min, h, d, w, ms, and us, meaning seconds, minutes,
hours, days, weeks, milliseconds, and microseconds, respectively. Full
names of the time units can be used too.
If multiple integers and units are specified, the time values are
summed. 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, e, v, q, Q, C, x
and X. If omitted or set to "-", no automatic clean-up is done.
If the age field starts with a tilde character "~", clean-up is only
applied to files and directories one level inside the directory
specified, but not the files and directories immediately inside it.
The age of a file system entry is determined from its last modification
timestamp (mtime), its last access timestamp (atime), and (except for
directories) its last status change timestamp (ctime). By default, any
of these three (or two) values will prevent cleanup if it is more recent
than the current time minus the age field. To restrict the deletion
based on particular type of file timestamps, the age-by argument can be
used.
The age-by argument overrides the timestamp types to be used for the age
check. It can be specified by prefixing the age argument with a sequence
of characters to specify the timestamp types and a colon (":"):
"age-by...:cleanup-age". The argument can consist of a (A for
directories), b (B for directories), c (C for directories), or m (M for
directories). Those respectively indicate access, creation, last status
change, and last modification time of a file system entry. The
lower-case letter signifies that the given timestamp type should be
considered for files, while the upper-case letter signifies that the
given timestamp type should be considered for directories. See statx(2)
file timestamp fields for more details about timestamp types.
If not specified, the age-by field defaults to abcmABM, i.e. by default
all file timestamps are taken into consideration, with the exception of
the last status change timestamp (ctime) for directories. This is
because the aging logic itself will alter the ctime whenever it deletes
a file inside it. To ensure that running the aging logic does not feed
back into the next iteration of itself, ctime for directories is ignored
by default.
For example:
# Files created and modified, and directories accessed more than
# an hour ago in "/tmp/foo/bar", are subject to time-based cleanup.
d /tmp/foo/bar - - - bmA:1h -
Note that while the aging algorithm is run an exclusive BSD file lock
(see flock(2)) is taken on each directory/file the algorithm decides to
remove. If the aging algorithm finds a lock (shared or exclusive) is
already taken on some directory/file, it (and everything below it) is
skipped. Applications may use this to temporarily exclude certain
directory subtrees from the aging algorithm: the applications can take a
BSD file lock themselves, and as long as they keep it aging of the
directory/file and everything below it is disabled.
This behavior can be used to ensure guaranteed cleanup of files or
directories whose lifetime should be aligned with the process that
created them by having that process create them in a location monitored
by systemd-tmpfiles with an age of "0", and having the process
immediately lock the directory or file before using it. Because the BSD
lock is process specific, the file is guaranteed to be unlocked as soon
as the process exits, meaning that even if the process crashes, those
files and directories will be unlocked and cleaned up by
systemd-tmpfiles.
Argument
For L lines determines the destination path of the symlink. For c and b,
determines the major/minor of the device node, with major and minor
formatted as integers, separated by ":", e.g. "1:3". For f and w, the
argument 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. For t and T, determines extended attributes to be set. For a
and A, determines ACL attributes to be set. For h and H, determines the
file attributes to set. Ignored for all other lines.
This field can contain specifiers, see below.
SPECIFIERS
Specifiers can be used in the "path" and "argument" fields. An unknown
or unresolvable specifier is treated as invalid configuration. The
following expansions are understood:
Table 1. Specifiers available
┌───────────┬──────────────────────┬────────────────────────┐
│ Specifier │ Meaning │ Details │
├───────────┼──────────────────────┼────────────────────────┤
│ "%a" │ Architecture │ A short string │
│ │ │ identifying the │
│ │ │ architecture of the │
│ │ │ local system. A │
│ │ │ string such as x86, │
│ │ │ x86-64 or arm64. See │
│ │ │ the architectures │
│ │ │ defined for │
│ │ │ ConditionArchitecture= │
│ │ │ in systemd.unit(5) │
│ │ │ for a full list. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%A" │ Operating system │ The operating system │
│ │ image version │ image version │
│ │ │ identifier of the │
│ │ │ running system, as │
│ │ │ read from the │
│ │ │ IMAGE_VERSION= field │
│ │ │ of /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%b" │ Boot ID │ The boot ID of the │
│ │ │ running system, │
│ │ │ formatted as string. │
│ │ │ See random(4) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%B" │ Operating system │ The operating system │
│ │ build ID │ build identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ BUILD_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%C" │ System or user cache │ In --user mode, this │
│ │ directory │ is the same as │
│ │ │ $XDG_CACHE_HOME, and │
│ │ │ /var/cache otherwise. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%g" │ User group │ This is the name of │
│ │ │ the group running the │
│ │ │ command. In case of │
│ │ │ the system instance │
│ │ │ this resolves to │
│ │ │ "root". │
├───────────┼──────────────────────┼────────────────────────┤
│ "%G" │ User GID │ This is the numeric │
│ │ │ GID of the group │
│ │ │ running the command. │
│ │ │ In case of the system │
│ │ │ instance this resolves │
│ │ │ to 0. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%h" │ User home directory │ This is the home │
│ │ │ directory of the user │
│ │ │ running the command. │
│ │ │ In case of the system │
│ │ │ instance this resolves │
│ │ │ to "/root". │
├───────────┼──────────────────────┼────────────────────────┤
│ "%H" │ Host name │ The hostname of the │
│ │ │ running system. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%l" │ Short host name │ The hostname of the │
│ │ │ running system, │
│ │ │ truncated at the first │
│ │ │ dot to remove any │
│ │ │ domain component. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%L" │ System or user log │ In --user mode, this │
│ │ directory │ is the same as │
│ │ │ $XDG_STATE_HOME with │
│ │ │ /log appended, and │
│ │ │ /var/log otherwise. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%m" │ Machine ID │ The machine ID of the │
│ │ │ running system, │
│ │ │ formatted as string. │
│ │ │ See machine-id(5) for │
│ │ │ more information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%M" │ Operating system │ The operating system │
│ │ image identifier │ image identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ IMAGE_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%o" │ Operating system ID │ The operating system │
│ │ │ identifier of the │
│ │ │ running system, as │
│ │ │ read from the ID= │
│ │ │ field of │
│ │ │ /etc/os-release. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%q" │ Pretty host name │ The pretty hostname of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ PRETTY_HOSTNAME= field │
│ │ │ of /etc/machine-info. │
│ │ │ If not set, resolves │
│ │ │ to the short hostname. │
│ │ │ See machine-info(5) │
│ │ │ for more information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%S" │ System or user state │ In --user mode, this │
│ │ directory │ is the same as │
│ │ │ $XDG_STATE_HOME, and │
│ │ │ /var/lib otherwise. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%t" │ System or user │ In --user mode, this │
│ │ runtime directory │ is the same │
│ │ │ $XDG_RUNTIME_DIR, and │
│ │ │ /run/ otherwise. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%T" │ Directory for │ This is either /tmp or │
│ │ temporary files │ the path "$TMPDIR", │
│ │ │ "$TEMP" or "$TMP" are │
│ │ │ set to. (Note that the │
│ │ │ directory may be │
│ │ │ specified without a │
│ │ │ trailing slash.) │
├───────────┼──────────────────────┼────────────────────────┤
│ "%u" │ User name │ This is the name of │
│ │ │ the user running the │
│ │ │ command. In case of │
│ │ │ the system instance │
│ │ │ this resolves to │
│ │ │ "root". │
├───────────┼──────────────────────┼────────────────────────┤
│ "%U" │ User UID │ This is the numeric │
│ │ │ UID of the user │
│ │ │ running the command. │
│ │ │ In case of the system │
│ │ │ instance this resolves │
│ │ │ to 0. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%v" │ Kernel release │ Identical to uname -r │
│ │ │ output. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%V" │ Directory for larger │ This is either │
│ │ and persistent │ /var/tmp or the path │
│ │ temporary files │ "$TMPDIR", "$TEMP" or │
│ │ │ "$TMP" are set to. │
│ │ │ (Note that the │
│ │ │ directory may be │
│ │ │ specified without a │
│ │ │ trailing slash.) │
├───────────┼──────────────────────┼────────────────────────┤
│ "%w" │ Operating system │ The operating system │
│ │ version ID │ version identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ VERSION_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%W" │ Operating system │ The operating system │
│ │ variant ID │ variant identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ VARIANT_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%%" │ Single percent sign │ Use "%%" in place of │
│ │ │ "%" to specify a │
│ │ │ single percent sign. │
└───────────┴──────────────────────┴────────────────────────┘
EXAMPLES
Example 1. Create directories with specific mode and ownership
screen(1), needs two directories created at boot with specific modes and
ownership:
# /usr/lib/tmpfiles.d/screen.conf
d /run/screens 1777 root screen 10d
d /run/uscreens 0755 root screen 10d12h
Contents of /run/screens and /run/uscreens will be cleaned up after 10
and 10½ days, respectively.
Example 2. Create a directory with a SMACK attribute
D /run/cups - - - -
t /run/cups - - - - security.SMACK64=printing user.attr-with-spaces="foo bar"
The directory will be owned by root and have default mode. Its contents
are not subject to time-based cleanup, but will be obliterated when
systemd-tmpfiles --remove runs.
Example 3. Create a directory and prevent its contents from cleanup
abrt(1), needs a directory created at boot with specific mode and
ownership and its content should be preserved from the automatic cleanup
applied to the contents of /var/tmp:
# /usr/lib/tmpfiles.d/tmp.conf
d /var/tmp 1777 root root 30d
# /usr/lib/tmpfiles.d/abrt.conf
d /var/tmp/abrt 0755 abrt abrt -
Example 4. Apply clean up during boot and based on time
# /usr/lib/tmpfiles.d/dnf.conf
r! /var/cache/dnf/*/*/download_lock.pid
r! /var/cache/dnf/*/*/metadata_lock.pid
r! /var/lib/dnf/rpmdb_lock.pid
e /var/cache/dnf/ - - - 30d
The lock files will be removed during boot. Any files and directories in
/var/cache/dnf/ will be removed after they have not been accessed in 30
days.
Example 5. Empty the contents of a cache directory on boot
# /usr/lib/tmpfiles.d/krb5rcache.conf
e! /var/cache/krb5rcache - - - 0
Any files and subdirectories in /var/cache/krb5rcache/ will be removed
on boot. The directory will not be created.
Example 6. Provision SSH public key access for root user via Credentials
in QEMU
-smbios type=11,value=io.systemd.credential.binary:tmpfiles.extra=$(echo -e "d /root/.ssh 0750 root root -\nf~ /root/.ssh/authorized_keys 0600 root root - $(ssh-add -L | base64 -w 0)" | base64 -w 0)
By passing this line to QEMU, the public key of the current user will be
encoded in base64, added to a tmpfiles.d line that tells systemd-
tmpfiles(8) to decode it into /root/.ssh/authorized_keys, encode that
line itself in base64 and pass it as a Credential that will be picked up
by systemd from SMBIOS on boot.
/RUN/ AND /VAR/RUN/
/var/run/ is a deprecated symlink to /run/, and applications should use
the latter. systemd-tmpfiles will warn if /var/run/ is used.
SEE ALSO
systemd(1), systemd-tmpfiles(8), systemd-delta(1), systemd.exec(5),
attr(5), getfattr(1), setfattr(1), setfacl(1), getfacl(1), chattr(1),
btrfs-subvolume(8), btrfs-qgroup(8)
NOTES
1. Base64 decoded
https://www.rfc-editor.org/rfc/rfc4648.html
2. System and Service Credentials
https://systemd.io/CREDENTIALS
3. Notes on Resolvability of User and Group Names
https://systemd.io/UIDS-GIDS/#notes-on-resolvability-of-user-and-group-names
systemd 257.9 TMPFILES.D(5)
Generated by dwww version 1.16 on Tue Dec 16 04:49:16 CET 2025.