NAME
tmpfiles.d - Configuration for creation, deletion and cleaning of volatile and temporary filesSYNOPSIS
/etc/tmpfiles.d/*.conf /run/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/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 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 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
Type
The type consists of a single letter and optionally one or emore 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 --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.
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.
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.
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.
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 or directory 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. Note that permissions and
ownership 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
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. 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.
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. 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.
T
Same as t, but operates
recursively.
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.
a, a+
Set POSIX ACLs (access control lists), see
acl(5). If suffixed with +, the specified entries will be added
to the existing set. systemd-tmpfiles 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.
A, A+
Same as a and a+, but recursive.
Does not follow symlinks.
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 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
# Modify sysfs but don't fail if we are in a container with a read-only /proc w- /proc/sys/vm/swappiness - - - - 10
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 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, L, 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 -
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, 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: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 image version | The operating system 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 build ID | The operating system 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 directory | In --user mode, this 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 directory | In --user mode, this is the same as $XDG_CONFIG_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 image identifier | The operating system 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. |
"%S" | System or user state directory | In --user mode, this is the same as $XDG_CONFIG_HOME, and /var/lib otherwise. |
"%t" | System or user runtime directory | In --user mode, this is the same $XDG_RUNTIME_DIR, and /run/ otherwise. |
"%T" | Directory for temporary files | This is either /tmp or the path "$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 and persistent temporary files | This is either /var/tmp or the path "$TMPDIR", "$TEMP" or "$TMP" are set to. (Note that the directory may be specified without a trailing slash.) |
"%w" | Operating system version ID | The operating system version identifier of the running system, as read from the VERSION_ID= field of /etc/os-release. If not set, resolves to an empty string. See os-release(5) for more information. |
"%W" | Operating system variant ID | The operating system variant identifier of the running system, as read from the VARIANT_ID= field of /etc/os-release. If not set, resolves to an empty string. See os-release(5) for more information. |
"%%" | Single percent sign | Use "%%" in place of "%" to specify a single percent sign. |
EXAMPLES
Example 1. Create directories with specific mode and ownership# /usr/lib/tmpfiles.d/screen.conf d /run/screens 1777 root screen 10d d /run/uscreens 0755 root screen 10d12h
D /run/cups - - - - t /run/cups - - - - security.SMACK64=printing user.attr-with-spaces="foo bar"
# /usr/lib/tmpfiles.d/tmp.conf d /var/tmp 1777 root root 30d
# /usr/lib/tmpfiles.d/abrt.conf d /var/tmp/abrt 0755 abrt abrt -
# /usr/lib/tmpfiles.d/dnf.conf r! /var/cache/dnf/*/*/download_lock.pid r! /var/cache/dnf/*/*/metadata_lock.pid r! /var/lib/dnf/rpmdb_lock.pid e /var/cache/dnf/ - - - 30d
# /usr/lib/tmpfiles.d/krb5rcache.conf e! /var/cache/krb5rcache - - - 0
-smbios type=11,value=io.systemd.credential.binary:tmpfiles.extra=$(echo "f~ /root/.ssh/authorized_keys 700 root root - $(ssh-add -L | base64 -w 0)" | base64 -w 0)
/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
- 2.
- System and Service Credentials
- 3.
- Notes on Resolvability of User and Group Names
systemd 252 |