udisks - Disk Manager


   udisks provides interfaces to enumerate and perform operations on disks
   and storage devices. Any application (including unprivileged ones) can
   access the udisksd(8) daemon via the name org.freedesktop.UDisks2 on
   the system message bus[1]. In addition to the D-Bus API, a library,
   libudisks2 is also provided. This library can be used from C/C++ and
   any high-level language with GObjectIntrospection[2] support such as
   Javascript and Python. udisks is only indirectly involved in what
   devices and objects are shown in the user interface. See these notes[3]
   for what is shown in GNOME 3.


   By default, logged-in users in active log-in sessions are permitted to
   perform operations (for example, mounting, unlocking or modifying) on
   devices attached to the seat their session is on. Access-control is
   fine-grained and based on polkit(8), see the "Authorization Checks"
   chapter in the udisks documentation for more information. Note that the
   x-udisks-auth option can be used in the /etc/fstab and /etc/crypttab
   files to specify that additional authorization is required to mount
   resp. unlock the device (typically requiring the user to authenticate
   as an administrator).


   At start-up and when a drive is connected, udisksd(8) will apply
   configuration stored in the file /etc/udisks2/IDENTIFIER.conf where
   IDENTIFIER is the value of the Drive:Id property for the drive. If the
   file changes on disk its new contents will also be applied to the
   drive. Typically, users or administrators will never need to edit drive
   configuration files as they are effectively managed through graphical
   applications such as gnome-disks(1). Manually editing configuration
   files is however supported --- the file format is a simple .ini-like
   format (see the Desktop Entry Specification[4] for the exact syntax).
   New groups and keys may be added in the future.

   ATA group
   The ATA group is for settings that apply to drives using the ATA
   command-set. The following keys are supported:

       The standby timeout. A value of zero means "timeouts are disabled":
       the device will not automatically enter standby mode. Values from 1
       to 240 specify multiples of 5 seconds, yielding timeouts from 5
       seconds to 20 minutes. Values from 241 to 251 specify from 1 to 11
       units of 30 minutes, yielding timeouts from 30 minutes to 5.5
       hours. A value of 252 signifies a timeout of 21 minutes. A value of
       253 sets a vendor-defined timeout period between 8 and 12 hours,
       and the value 254 is reserved. 255 is interpreted as 21 minutes
       plus 15 seconds. Note that some older drives may have very
       different interpretations of these values. This is similar to the
       -S option in hdparm(8).

       The Advanced Power Management level. A low value means aggressive
       power management and a high value means better performance.
       Possible settings range from values 1 through 127 (which permit
       spin-down), and values 128 through 254 (which do not permit
       spin-down). The highest degree of power management is attained with
       a setting of 1, and the highest I/O performance with a setting of
       254. A value of 255 can be used to disable Advanced Power
       Management altogether on the drive (not all drives support
       disabling it, but most do). This is similar to the -B option in

       The Automatic Acoustic Management level. Most modern harddisk
       drives have the ability to speed down the head movements to reduce
       their noise output. The possible values are between 0 and 254. 128
       is the most quiet (and therefore slowest) setting and 254 the
       fastest (and loudest). Some drives have only two levels (quiet /
       fast), while others may have different levels between 128 and 254.
       At the moment, most drives only support 3 options, off, quiet, and
       fast. These have been assigned the values 0, 128, and 254 at
       present, respectively, but integer space has been incorporated for
       future expansion, should this change. This is similar to the -M
       option in hdparm(8).

       A boolean specifying whether to enable or disable the Write Cache.
       Valid values for this key are "true" and "false". This is similar
       to the -W option in hdparm(8). This key was added in 2.1.

       A boolean specifying whether to enable or disable the Read
       Look-ahead. Valid values for this key are "true" and "false". This
       is similar to the -A option in hdparm(8). This key was added in


   udisks relies on recent versions of udev(7) and the Linux kernel.
   Influential device properties in the udev database include:

       If set, this overrides the value of the HintSystem property.

       If set, this overrides the value of the HintIgnore property.

       If set, this overrides the value of the HintAuto property.

       If set, this overrides the value of the CanPowerOff property.

       The name to use for the device when presenting it in an user
       interface. This corresponds to the HintName property.

       The icon to use for the device when presenting it in an user
       interface. If set, the name must adhere to the freedesktop.org icon
       theme specification[5]. This corresponds to the HintIconName

       The icon to use for the device when presenting it in an user
       interface using a symbolic icon. If set, the name must adhere to
       the freedesktop.org icon theme specification[5]. This corresponds
       to the HintSymbolicIconName property.

       If set to 1, the filesystem on the device will be mounted in a
       shared directory (e.g.  /media/VolumeName) instead of a private
       directory (e.g.  /run/media/$USER/VolumeName) when the
       Filesystem.Mount() method is handled.

       The physical seat the device is attached to. If unset or set to the
       empty string, "seat0" (the first seat) is assumed.


   udisks guarantees a stable D-Bus API within the same major version and
   this guarantee also extends to the client-side library libudisks2.
   Additionally, several major versions of udisks can be installed and
   operate at the same time although interoperability may be limited - for
   example, a device mounted using the udisks N.x API may require
   additional authorization if attempting to unmount it through the the
   (N-1).x API.

   The udisks developers do not anticipate breaking API but does reserve
   the right to do so and if it happens, promises to bump the major
   version and ensure the new major version of udisks is
   parallel-installable with any older major version. However, note that
   programs, man pages and other artifacts may change name (for example,
   adopt a "2" suffix) to make room for the next major version. Therefore,
   applications can not rely on tools like e.g.  udisksctl(1) to be
   available. Additionally, there is no guarantee that the options,
   command-line switches etc. of command-line tools or similar will remain

   Instead, applications should only use the D-Bus API, the libudisks2
   library or tools such as dbus-send(1) or gdbus(1) to interact with


   The intended audience of udisks include operating system developers
   working on the higher-level parts of the operating system, for example
   the desktop shell (such as GNOME[6]) and disk management applications
   (e.g. GNOME's Disks[7] application). Software on this level typically
   depend on a specific (major) version of udisks and may even have
   support for previous versions of udisks or alternative interfaces
   performing the same role as udisks.

   While udisks indeed provides a stable API and a clear upgrade path, it
   may not be an appropriate dependency for third party applications. For
   example, if the operating system switches to udisks version N.x and an
   application is still using the udisks (N-1).x API, the application will
   not work unless udisks (N-1).x is installed. While this situation is
   still workable (since both udisks N.x and udisks (N-1).x can be
   installed) it may not be desirable to ask the user to install the old
   version - in fact, the operating system vendor may not even provide a
   packaged version of the old version. Hence, if an application does not
   want to tie itself to a specific version of the operating system, it
   should not use udisks.

   Viable alternatives to udisks are APIs that are guaranteed to be around
   for longer time-frames, including:

   *   Low-level APIs and commands such as e.g.  sysfs[8], libudev[9],
       /proc/self/mountinfo[10] and util-linux[11].

   *   High-level APIs such as GVolumeMonitor[12].

   In particular, for desktop applications it is a much better idea to use
   something like GVolumeMonitor since it will make the application show
   the same devices as the desktop shell (e.g. file manager, file chooser
   and so on) is showing.


   Written by David Zeuthen <zeuthen@gmail.com> with a lot of help from
   many others.


   Please send bug reports to either the distribution bug tracker or the
   upstream bug tracker at


   udev(7), polkit(8), udisksd(8), udisksctl(1), umount.udisks2(8), gnome-


    1. system message bus

    2. GObjectIntrospection

    3. notes

    4. Desktop Entry Specification

    5. freedesktop.org icon theme specification

    6. GNOME

    7. Disks

    8. sysfs

    9. libudev

   10. /proc/self/mountinfo

   11. util-linux

   12. GVolumeMonitor


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.