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gnome-mount

gnome-mount

Section: User Commands (1)
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NAME

gnome-mount - Mount drives and volumes using HAL and read settings from the GNOME desktop configuration system gconf.  

SYNOPSIS

gnome-mount [-?|--help] [-v] [-n] [-t] [-b] [-d /dev/file | -h /org/fd/Hal/udi | -p nickname] [--unmount | --eject | --write-settings | --erase-settings | --show-settings] [--mount-point where-to-mount] [--mount-options opt1,opt2=foo,opt3] [--extra-mount-options opt4,opt5=bar] [--fstype fstype-to-use]

 

DESCRIPTION

This program is used to mount and unmount file systems for GNOME desktop users. It can also be used to eject discs from CD drives and other devices that needs to be ejected. For example, iPod's needs this to make the "Do not disconnect" message go away.

Normally, this program is invoked by software in the GNOME stack (specifically gnome-vfs-daemon and gnome-volume-manager ). End users should never have to deal with gnome-mount directly on the command line, nor should they have to read this manual page.

Mounting a file system into the root file system involves a certain degree of configuration and as such is subject to whatever preferences an user might have. gnome-mount allows the user to control the mount point location, the mount options and what file system to use for mounting a file system. The settings are read from the gconf database (which is per-user) and can also be overridden on the command line using the appropriate parameters. See below.

 

SPECIFYING THE TARGET

The target (e.g. the partition or file system to mount, unmount or eject) can be specified using the HAL UDI (Unique Device Identifier), e.g. /org/freedesktop/Hal/devices/volume_uuid_E18B_10EC , the name of the special device file, e.g. /dev/sda1 or a pseudonym. The latter is a textual string used to locate the target and it makes gnome-mount search for the target by comparing the given textual string to the mount points and file system labels.

 

DETERMINING SETTINGS

Settings (e.g. mount point, mount options, file system type) are read in the order below. Note that each option is treated individually; for example it is valid for a drive to only specify the mount point setting and not the mount options. Also note that the even if the drive specifies mount options, these can be overridden on a per-volume basis.

FILE SYSTEM DEFAULTS
First, default mount options are read from /system/storage/defaults/FS_TYPE/ for the probed file system type of the volume. The option uid=, is treated specially by gnome-mount and will be replaced by uid=UID_OF_USER to cope with the fact that the uid is a function of the user calling it.

PER DRIVE
Second, the gconf tree at /system/storage/drives/UDI_OF_DRIVE/ is consulted for options that depend on what drive the volume belongs to. For example, this is useful for configuring that volumes inserted into a given drive is always mounted at the same location. For example, this can be used to emulate /etc/fstab behaviour by where CD media is always mounted at e.g. /media/cdrom

PER VOLUME
Third, the gconf tree at /system/storage/drives/UDI_OF_VOLUME/ is consulted for options that are specific to a particular piece of media and as such depends on either the file system label (e.g. EOS_DIGITAL ) or the file system UUID (e.g. E18B_10EC ) or both.

COMMANDLINE OPTIONS
Users can pass --mount-point , --mount-options or --fstype on the commandline to override settings.

EXTRA COMMANDLINE OPTIONS
Finally, if mount options are passed via --extra-mount-options these are not replacing the mount options, they are simply added. This is useful for doing e.g.


 gnome-mount --extra-mount-options remount,exec -d /dev/sda1

to remount a volumes such that programs can be run from the media. This is useful for e.g. gnome-volume-manager if it discovers an autorun file on the media.

 

PASSWORDED MEDIA

gnome-mount supports passworded media through the org.freedesktop.Hal.Device.Volume.Crypto interface supported by HAL and this includes volumes formatted in a way that adheres to the LUKS (Linux Unified Key Setup) specification. In addition, gnome-mount uses gnome-keyring to retrieve and store the pass phrase. If no key can be retrieved, gnome-mount will prompt the user for one. In addition, if the keyring is locked, the user may be prompted to unlock it via standard gnome-keyring mechanisms.

 

PRIVILEGES

gnome-mount is intended for unprivileged users and HAL ultimately controls if the calling user is allowed to mount, unmount or eject volumes as well as what mount options are valid. As such, requests may be denied. See the (human readable) exception returned from HAL for details if a request fails.

Note that HAL has a notion of what mount options are valid for a given volume. They are listed in the HAL property volume.mount.valid_options on the device object representing the volume to mount. Consult lshal(1) for details. Also note that HAL by default appends the options nosuid and nodev to prevent privilege escalation.

In addition to using HAL as the mechanism for mounting file systems, the /etc/fstab file is also consulted as HAL will refuse to mount any file system listed in this file as it would violate system policy. If this is the case, gnome-mount will invoke mount(1) as the calling user rather than invoking the Mount method on the org.freedesktop.Hal.Device.Volume interface on the device object representing the volume / drive. This means that settings (mount point, mount options, file system type) read by gnome-mount are not passed along as these are already specified in the /etc/fstab file and there are no mechanism to override them. When parsing the /etc/fstab file, gnome-mount (and also HAL for that matter) resolves symbolic links and also respects the LABEL= and UUID= notations. For example, if this line is in /etc/fstab


 LABEL=MyVolume /mnt/myvolume auto user,defaults 0 0

then gnome-mount mounts the file system with the label MyVolume via mount(1) and /etc/fstab rather than using the HAL mechanisms.

 

OPTIONS

Options available for the gnome-mount command:

-v, --verbose
Verbose operation, shows debug messages.

-n, --no-ui
Don't show any dialogs the user needs to dismiss. If X11 is available, gnome-mount may pop up transient notification bubbles e.g. suggesting the user to remount a volume with different options to streamline access to file systems with ownership attributes. This is the option that storage policy daemons such as gnome-volume-manager should invoke gnome-mount in. File managers, however, such as Nautilus , should never use this option as the user should get e.g. an error dialog if he tries to access a volume with a missing, unsupported or unknown file system.

-b, --block
Allow gnome-mount to block even if an error occured. By default, gnome-mount will daemonize so it can return control to the invoking application as soon as possible (e.g. when an operation either fails or succeeds ) while still showing an error dialog to the end user. Useful when debugging.

-u, --unmount
Use this for unmounting rather than mounting. If gnome-mount is invoked as gnome-umount (a symlink to gnome-mount ) then this option is automatically selected.

-e, --eject
Use this for ejecting rather than mounting. If gnome-mount is invoked as gnome-eject (a symlink to gnome-mount ) then this option is automatically selected.

-d, --device
Specify target volume by the special device file.

-h, --hal-udi
Specify target volume by HAL UDI (Unique Device Identifier).

-p, --pseudonym
Specify target volume by pseudonym. See above for how this works.

-t, --text
Never use X11 dialogs or notification bubbles even if an X11 server is available. Also prohibits the use of gnome-keyring to retrieve pass phrases for passworded media because this might require unlocking the keyring which happens through an X11 dialog out of process. Useful for command line operation.

-m, --mount-point
Specify mount point to use; don't include /media as this is automatically appened by the mechanism used to mount, e.g. the HAL methods.

-o, --mount-options
Specify mount options. Separate by comma.

-f, --fstype
Specify file system type. This is useful for using e.g. the msdos file system instead of the vfat file system.

--write-settings
Instead of mounting a drive, specify what options to store in the gconf database. Can be used on both drives and volumes. Be careful using this with the --device option as optical drives (among others) use the same special device file for both the drive and the volume. One trick is to ensure the optical drive has no media when configuring it via this option. Another possibility is to use the HAL UDI instead.

--display-settings
Display settings for a drive or volume.

--erase-settings
Erase settings for a drive or volume.

 

RETURN CODES

gnome-mount will return zero if the request succeeded or non-zero if it failed. Note that gnome-mount is specifically designed to run in a graphical user environment and as such all error reporting (and resolution) is through X11 dialogs. For example, if HAL reports that a volume could not be mounted because of a missing file system driver, gnome-mount might, one day, launch a tool to ask the user if he wants to download and install the driver. In a similar way, all error dialogs are presented via X11 dialogs to the user as well.

 

EXAMPLE

We want to make sure that the discs inserted into an optical drive are always mounted at /media/cdrecorder instead of using the default which is using the label specified in the iso9660 or udf file system header. Assuming that the drive is empty and the special device file for the drive is /dev/hdc the following command will work


    gnome-mount --write-settings
                --device /dev/hdc
                --mount-point cdrecorder

This can be inspected via the --display-settings option and the settings can also be erased via the --erase-settings option. Also note that gconf-editor(1) can be used for tasks like these.

 

HARDWARE THAT CANNOT BE POLLED

HAL polls most storage devices for media insertion / removal and maintains the list of devices exported. However, some hardware cannot be polled for media changes without making noise or for other reasons. PC floppy drives, Zip drives connected through an IDE interface and broken optical drives falls into this category.

For such hardware HAL only exports the drive and rather than exporting volume as childs of the drive, the org.freedesktop.Hal.Device.Volume interface is exported on the drive itself. gnome-mount supports this but it means that it is impossible to know ahead of time what file system is on the media in the problematic drive, so in this case gnome-mount passes auto as the file system type and passes the mount options uid=UID_OF_USER as most media in such devices are formatted with either the vfat , udf or iso9660 file systems.

This also means that per-volume settings are not possible; one can only specify settings per-drive.

 

AUTHOR

gnome-mount was written by David Zeuthen <david@fubar.dk>.

 

SEE ALSO

fstab(5), mount(8), umount(8), eject(1), cryptsetup(8), gconftool-2(1), gconf-editor(1), lshal(1)

http://www.gnome.org/projects/gconf/

http://en.wikipedia.org/wiki/GNOME_Keyring

http://freedesktop.org/Software/hal

http://luks.endorphin.org


 

Index

NAME
SYNOPSIS
DESCRIPTION
SPECIFYING THE TARGET
DETERMINING SETTINGS
PASSWORDED MEDIA
PRIVILEGES
OPTIONS
RETURN CODES
EXAMPLE
HARDWARE THAT CANNOT BE POLLED
AUTHOR
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 22:34:18 GMT, April 16, 2011