virtualbox.org

Hi,
Linux guests are provided by V.B. with special file system to support shared folders: vboxsf (pseudo (?)) file system.
Adequately the mount utility must to have a helper for this file system, vboxsf available.
Mount will surely not serve the vboxsf pseude file system in direct way.

Is a manual available for command line vboxsf interface, as to be used in context of mount?
There are thousands discussions in web how to solve certain problem, achieve certain goal,
will certain vboxsf options [mount -t vboxsf -o OPTIONS] discussed but no manual in one piece was found.

I just like ask for confirmation respectively disagreement regarding current status.

Shared folders require that the guest has the guest additions installed. As for instructions you have that already if you have installed the official version of VirtualBox from virtualbox.org. You can find it under the help in both the GUI main manager and the guest. You can also read it on line from http://www.virtualbox.org/manual/UserManual.html. Read chapter 4 and your answers are there. The following link also explains in detail how to mount shared folders and install guest additions viewforum.php?f=29

Sure, the V.B. manual had been consulted yet before opening this thread.
Guest Additions is a big conglomerate, it provides plenty of extension features,
its feature portfolio covers amongst other screen high resolutions, mouse capturing, seamless mode,
drag & drop, shared clipboard, named shared folders. Possibly much more, I use just a small sub-set.
I doubt all these features are implemented in one single piece of software.
Guest Additions have surely modular build rather than monolithic one, comprised of sub-systems.
Particular sub-system responsible for assigned function.
Adequately an internal block for shared folders. The shared folders implementation basis
is different for e.g. Windows as for Linux guests, means network protocol vs. file system.
I guess I could see this information in manual your are referring to, or similar place.
In this case according to V.B. documentation the name of used file system is vboxsf.

Furthermore, mount guest program which is involved in attaching shared folder to guest
is referring to helper programs in case of exotic file system. vboxsf is surely exotic from
mount's point of view. I doubt mount implements it directly.
Rather it will seek to call a helper program if user is referring to vboxsf.

Instructions in manual were great but not sufficient as for the type of our guest - Ubuntu -
all mounts are made by root (or user with admin rights), they are used however by normal
users without admin privileges - inclusively host-guest shared folders.
The most important point - user needs full access to host-guest shared folders.
By applying merely the instructions from V.B. manual it was not possible to achieve target.
Additional measures were needed in order to achieve the goal: shared folder, transient, attached
to guest on-the-fly without reboot is needed, full access by user without administrative rights.
Special options in mount command were necessary and found in web but not in V.B. documentation.
vboxsf does not seem to deliver with man page.

There are in web several places with vboxsf specific mount options described but
a collection of all them in one single man page or similar seems to still fail - at least from my experience.
Unless one can tell the opposite (?)

Not sure where this is going, but I can tell you that if you do not install the guest additions ( in the guest ) then you have absolutely no possibility of success. As for what is required on the guest to mount anything, that is controlled by the guest OS and not VirtualBox so if you have issues with the mount you need to talk to them.

Of course, guest additions had been installed at very beginning, this is the first prerequisite to be fulfilled.

> ..hat is controlled by the guest OS and not VirtualBox so if you have issues with the mount you need to talk to them.
I am doing that - this question/thread was open in Linux Guests forum.

vboxsf - which is the foundation of Shared Folders in case of V.B. and Linux guest - is V.B. specific topic, not a guest distro specific one.

I see you have a misconception that we teach Linux, we do not. If the guest is Debian you use the Debian forum, Ubuntu you use the Ubuntu forums and so on. They have a large number of folks that can tell you why it requires root permission to mount devices and shares.

Anyhow, I still believe the vboxsf - which is the foundation of Shared Folders in case of V.B. and Linux guest - and is provided by V.B. Guest Additions, not the guest Linux - is V.B. specific topic, not a guest distro specific one.
Will vboxsf be present on any V.B.-free Linux distro, means Linux distro installed on physical machine, or on virtual one but virtualization solution other than V.B.?

From the Vbox manual, chpt. 4.3.1:
Beyond the standard options supplied by the mount command, the following are available:
iocharset CHARSET
to set the character set used for I/O operations. Note that on Linux guests, if the "iocharset" option is not specified then the Guest Additions driver will attempt to use the character set specified by the CONFIG_NLS_DEFAULT kernel option. If this option is not set either then UTF-8 will be used. Also,
convertcp CHARSET
is available in order to specify the character set used for the shared folder name (utf8 by default).
The generic mount options (documented in the mount manual page) apply also. Especially useful are the options uid, gid and mode, as they allow access by normal users (in read/write mode, depending on the settings) even if root has mounted the filesystem.

In additions to what Martin said, the vboxsf presented by VirtualBox is just a file type. and is handled exactly the say way as any device in the OS. Exactly the same way as you mount extra hard drives, or NFS shares.

Thank you for all your input. I read the manual chapter not careful enough to its end.

According to ch. 4.3
For Windows guests, shared folders are implemented as a pseudo-network redirector;
for Linux and Solaris guests, the Guest Additions provide a virtual file system.

Unfortunately, mount man page does not mention options uid, gid, mode neither in
generic section nor in file system independent options section.
Mount man page as provided by Ubuntu 14.04 LTS is used.
These options can be found in some mount man page f.s. specific sections.

Anyhow, as for me my question is answered. Thank you again.