storagectl, mount.storage — Enumerate and mount storage volumes provided by storage providers
storagectl [OPTIONS...] {COMMAND} [NAME...]
mount -t storage PROVIDER:VOLUME DIRECTORY
mount -t storage.FSTYPE PROVIDER:VOLUME DIRECTORY
storagectl may be used to inspect storage providers and the storage
volumes they expose. A storage provider is a service implementing the
io.systemd.StorageProvider Varlink
interface, registered as an AF_UNIX socket below the well-known socket directory
/run/systemd/io.systemd.StorageProvider/ (in system mode) or
$XDG_RUNTIME_DIR/systemd/io.systemd.StorageProvider/ (in user mode). The two
storage providers shipped with systemd are
systemd-storage-block@.service(8),
which exposes the system's block devices, and
systemd-storage-fs@.service(8),
which exposes regular files and directories from a backing file system.
The tool also provides a mount(8) helper
for the file system type "storage", which permits mounting storage volumes to arbitrary
places. See "Use as a mount helper" below for details.
The following commands are understood:
GLOB]¶List storage volumes provided by all storage providers running on the
system (or, with --user, in the user runtime). The optional
GLOB argument is a shell-style pattern (see
fnmatch(3))
that filters the result by volume name. The output is a table containing the providing
service, the volume name, its type ("blk", "reg" or
"dir"), whether it is read-only, and — if known — its size and the number
of bytes used.
This is the default command if none is specified.
GLOB]¶List volume templates supported by the running storage providers. Templates
encapsulate a configuration to use when creating volumes on-the-fly, when they are acquired. Template
support is an optional feature for providers, and only applies to providers that allow creation
of volumes on-the-fly. See the respective provider documentation for details, for example
systemd-storage-fs@.service(8). The
optional GLOB argument filters by template name. Storage providers that do
not implement template-based volume creation (such as the block-device provider) do not contribute to
this output.
List the storage providers known to the system. This is determined by scanning the
well-known socket directory for AF_UNIX sockets that look like
io.systemd.StorageProvider endpoints. For each provider it is also reported
whether the socket can currently be connected to.
The following options are understood:
--system¶Operate on system-wide storage providers. Sockets are looked for in
/run/systemd/io.systemd.StorageProvider/. This is the default.
--user¶Operate on per-user storage providers. Sockets are looked for in
$XDG_RUNTIME_DIR/systemd/io.systemd.StorageProvider/.
--json=MODE¶Shows output formatted as JSON. Expects one of "short" (for the
shortest possible output without any redundant whitespace or line breaks), "pretty"
(for a pretty version of the same, with indentation and line breaks) or "off" (to turn
off JSON output, the default).
--no-pager¶Do not pipe output into a pager.
--no-legend¶Do not print the legend, i.e. column headers and the footer with hints.
--no-ask-password¶Do not query the user for authentication for privileged operations.
-h, --help¶--version¶The tool provides the /sbin/mount.storage alias, implementing the
mount(8)
"external helper" interface, allowing storage volumes to be mounted with the regular
mount command. The volume to mount is encoded as the source of the mount,
in the form
"PROVIDER:VOLUMEPROVIDER is the name of a storage provider (as listed by
storagectl providers) and VOLUME is the volume
name. Two file system type spellings are recognized:
The standard -o mount options are forwarded to
mount. In addition, the following "storage."-prefixed
options are interpreted by mount.storage itself and stripped from the
forwarded list:
storage.create=MODE¶Takes one of "any" (open if it exists, otherwise create — the
default), "open" (fail if the volume does not yet exist) or "new"
(fail if the volume already exists).
storage.template=NAME¶The template to use when creating a new volume, if it is missing and the provider supports on-the-fly creation of volumes.
storage.create-size=BYTES¶When creating a new volume on-the-fly, the size in bytes to allocate. Accepts the
usual "K"/"M"/"G"/"T" suffixes
(base 1024). Required when creating a regular file volume.
Example 1. Enumerate available storage providers, volumes and templates
$ storagectl providers $ storagectl volumes $ storagectl volumes '*foo*' $ storagectl templates
Example 2. Mount a directory volume from the file system provider
# mount -t storage fs:myvol /mnt/myvol
If the volume "myvol" does not yet exist, it will be created using
the default "subvolume" template.
Example 3. Create and mount an ext4 file system from a regular file.
# mount -t storage.ext4 fs:scratch /mnt/scratch -o loop
Example 4. Mount a block device volume read-only
# mount -t storage.ext4 -o ro block:/dev/disk/by-id/usb-foo /mnt/foo
$SYSTEMD_LOG_LEVEL¶The maximum log level of emitted messages (messages with a higher
log level, i.e. less important ones, will be suppressed). Takes a comma-separated list of values. A
value may be either one of (in order of decreasing importance) emerg,
alert, crit, err,
warning, notice, info,
debug, or an integer in the range 0…7. See
syslog(3)
for more information. Each value may optionally be prefixed with one of console,
syslog, kmsg or journal followed by a
colon to set the maximum log level for that specific log target (e.g.
SYSTEMD_LOG_LEVEL=debug,console:info specifies to log at debug level except when
logging to the console which should be at info level). Note that the global maximum log level takes
priority over any per target maximum log levels.
$SYSTEMD_LOG_COLOR¶A boolean. If true, messages written to the tty will be colored according to priority.
This setting is only useful when messages are written directly to the terminal, because journalctl(1) and other tools that display logs will color messages based on the log level on their own.
$SYSTEMD_LOG_TIME¶A boolean. If true, console log messages will be prefixed with a timestamp.
This setting is only useful when messages are written directly to the terminal or a file, because journalctl(1) and other tools that display logs will attach timestamps based on the entry metadata on their own.
$SYSTEMD_LOG_LOCATION¶A boolean. If true, messages will be prefixed with a filename and line number in the source code where the message originates.
Note that the log location is often attached as metadata to journal entries anyway. Including it directly in the message text can nevertheless be convenient when debugging programs.
$SYSTEMD_LOG_TID¶A boolean. If true, messages will be prefixed with the current numerical thread ID (TID).
Note that the this information is attached as metadata to journal entries anyway. Including it directly in the message text can nevertheless be convenient when debugging programs.
$SYSTEMD_LOG_TARGET¶The destination for log messages. One of
console (log to the attached tty), console-prefixed (log to
the attached tty but with prefixes encoding the log level and "facility", see syslog(3),
kmsg (log to the kernel circular log buffer), journal (log to
the journal), journal-or-kmsg (log to the journal if available, and to kmsg
otherwise), auto (determine the appropriate log target automatically, the default),
null (disable log output).
$SYSTEMD_LOG_RATELIMIT_KMSG¶ Whether to ratelimit kmsg or not. Takes a boolean.
Defaults to "true". If disabled, systemd will not ratelimit messages written to kmsg.
$SYSTEMD_PAGER, $PAGER¶Pager to use when --no-pager is not given.
$SYSTEMD_PAGER is used if set; otherwise $PAGER is used.
If neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known
pager implementations is tried in turn, including
less(1)
and
more(1),
until one is found. If no pager implementation is discovered, no pager is invoked. Setting those
environment variables to an empty string or the value "cat" is equivalent to passing
--no-pager.
Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER
and $PAGER can only be used to disable the pager (with "cat" or
""), and are otherwise ignored.
$SYSTEMD_LESS¶Override the options passed to less (by default
"FRSXMK").
Users might want to change two options in particular:
K¶This option instructs the pager to exit immediately when Ctrl+C is pressed. To allow less to handle Ctrl+C itself to switch back to the pager command prompt, unset this option.
If the value of $SYSTEMD_LESS does not include "K",
and the pager that is invoked is less,
Ctrl+C will be ignored by the
executable, and needs to be handled by the pager.
X¶This option instructs the pager to not send termcap initialization and deinitialization strings to the terminal. It is set by default to allow command output to remain visible in the terminal even after the pager exits. Nevertheless, this prevents some pager functionality from working, in particular paged output cannot be scrolled with the mouse.
Note that setting the regular $LESS environment variable has no effect
for less invocations by systemd tools.
See less(1) for more discussion.
$SYSTEMD_LESSCHARSET¶Override the charset passed to less (by default "utf-8", if
the invoking terminal is determined to be UTF-8 compatible).
Note that setting the regular $LESSCHARSET environment variable has no effect
for less invocations by systemd tools.
$SYSTEMD_PAGERSECURE¶Common pager commands like less(1), in
addition to "paging", i.e. scrolling through the output, support opening of or writing to other files
and running arbitrary shell commands. When commands are invoked with elevated privileges, for example
under sudo(8) or
pkexec(1), the
pager becomes a security boundary. Care must be taken that only programs with strictly limited
functionality are used as pagers, and unintended interactive features like opening or creation of new
files or starting of subprocesses are not allowed. "Secure mode" for the pager may be enabled as
described below, if the pager supports that (most pagers are not written in a way
that takes this into consideration). It is recommended to either explicitly enable "secure mode" or to
completely disable the pager using --no-pager or PAGER=cat when
allowing untrusted users to execute commands with elevated privileges.
This option takes a boolean argument. When set to true, the "secure mode" of the pager is
enabled. In "secure mode", LESSSECURE=1 and PAGERSECURE=1 will be set
when invoking the pager, which instructs the pager to disable commands that open or create new files or
start new subprocesses.
Currently only less(1) and
more(1) are known
to understand these variables, respectively, and implement "secure mode".
When set to false, no limitation is placed on the pager. Setting
SYSTEMD_PAGERSECURE=0 or not removing it from the inherited environment may allow
the user to invoke arbitrary commands.
When $SYSTEMD_PAGERSECURE is not set, systemd tools attempt to automatically
figure out if "secure mode" should be enabled and whether the pager supports it. "Secure mode" is
enabled if the effective UID is not the same as the owner of the login session, see
geteuid(2)
and
sd_pid_get_owner_uid(3),
or when running under
sudo(8) or similar
tools ($SUDO_UID is set [1]). In those cases,
SYSTEMD_PAGERSECURE=1 will be set and pagers which are not known to implement
"secure mode" will not be used at all. Note that this autodetection only covers the most common
mechanisms to elevate privileges and is intended as convenience. It is recommended to explicitly set
$SYSTEMD_PAGERSECURE or disable the pager.
Note that if the $SYSTEMD_PAGER or $PAGER variables are to
be honoured, other than to disable the pager, $SYSTEMD_PAGERSECURE must be set
too.
$SYSTEMD_COLORS¶Takes a boolean argument, or a special value. By default (unset), systemd
and related utilities will use colors in their output if possible. If $COLORTERM
is set to "truecolor" or "24bit", 24-bit colors will be enabled,
256 colors otherwise, unless $NO_COLOR or $TERM indicates
colors are disabled.
true¶Same as unset, except that $NO_COLOR is ignored.
false¶The output will be monochrome.
16", "256", "24bit"¶Always use the base 16 ANSI colors, 256 colors, or 24 bit color, respectively.
auto-16", "auto-256", "auto-24bit"¶Use the given quantity of colours, subject to $TERM, and what
the console is connected to.
$SYSTEMD_URLIFY¶The value must be a boolean. Controls whether clickable links should be generated in
the output for terminal emulators supporting this. This can be specified to override the decision that
systemd makes based on $TERM and other conditions.
systemd(1), systemd-storage-block@.service(8), systemd-storage-fs@.service(8), varlinkctl(1), mount(8)
[1] It is recommended for other tools to set and check $SUDO_UID as appropriate,
treating it is a common interface.