NAME

       guestmount - Mount a guest filesystem on the host using FUSE and libguestfs

SYNOPSIS

        guestmount [--options] -a disk.img -m device [--ro] mountpoint

        guestmount [--options] -a disk.img -i [--ro] mountpoint

        guestmount [--options] -d Guest -i [--ro] mountpoint

WARNING

       You must not use "guestmount" in read-write mode on live virtual machines.  If you do
       this, you risk disk corruption in the VM.

DESCRIPTION

       The guestmount program can be used to mount virtual machine filesystems and other disk
       images on the host.  It uses libguestfs for access to the guest filesystem, and FUSE (the
       "filesystem in userspace") to make it appear as a mountable device.

       Along with other options, you have to give at least one device (-a option) or libvirt
       domain (-d option), and at least one mountpoint (-m option) or use the -i inspection
       option or the --live option.  How this works is better explained in the guestfish(1)
       manual page, or by looking at the examples below.

       FUSE lets you mount filesystems as non-root.  The mountpoint must be owned by you, and the
       filesystem will not be visible to any other users unless you make certain global
       configuration changes to "/etc/fuse.conf".  To unmount the filesystem, use the
       guestunmount(1) command.

EXAMPLES

       For a typical Windows guest which has its main filesystem on the first partition:

        guestmount -a windows.img -m /dev/sda1 --ro /mnt

       For a typical Linux guest which has a /boot filesystem on the first partition, and the
       root filesystem on a logical volume:

        guestmount -a linux.img -m /dev/VG/LV -m /dev/sda1:/boot --ro /mnt

       To get libguestfs to detect guest mountpoints for you:

        guestmount -a guest.img -i --ro /mnt

       For a libvirt guest called "Guest" you could do:

        guestmount -d Guest -i --ro /mnt

       If you don't know what filesystems are contained in a guest or disk image, use
       virt-filesystems(1) first:

        virt-filesystems -d MyGuest

       If you want to trace the libguestfs calls but without excessive debugging information, we
       recommend:

        guestmount [...] --trace /mnt

       If you want to debug the program, we recommend:

        guestmount [...] --trace --verbose /mnt

       To unmount the filesystem after using it:

        guestunmount /mnt

NOTES

   Other users cannot see the filesystem by default
       If you mount a filesystem as one user (eg. root), then other users will not be able to see
       it by default.  The fix is to add the FUSE "allow_other" option when mounting:

        sudo guestmount [...] -o allow_other /mnt

   Enabling FUSE
       On some distros, you may need to add yourself to a special group (eg. "fuse") before you
       can use any FUSE filesystem.  This is necessary on Debian and derivatives.

       On other distros, no special group is required.  It is not necessary on Fedora or Red Hat
       Enterprise Linux.

   fusermount error: "Device or resource busy"
       You can see this error when another process on the system jumps into the mountpoint you
       have just created, holding it open and preventing you from unmounting it.  The usual
       culprits are various GUI "indexing" programs.

       The popular workaround for this problem is to retry the "fusermount -u" command a few
       times until it works (guestunmount(1) does this for you).  Unfortunately this isn't a
       reliable fix if (for example) the mounted filesystem is particularly large and the
       intruding program particularly persistent.

       A proper fix is to use a private mountpoint by creating a new mount namespace using the
       Linux-specific clone(2)/unshare(2) flag "CLONE_NEWNS".  Unfortunately at the moment this
       requires root and we would also probably need to add it as a feature to guestmount.

   Race conditions possible when shutting down the connection
       When guestunmount(1)/fusermount(1) exits, guestmount may still be running and cleaning up
       the mountpoint.  The disk image will not be fully finalized.

       This means that scripts like the following have a nasty race condition:

        guestmount -a disk.img -i /mnt
        # copy things into /mnt
        guestunmount /mnt
        # immediately try to use 'disk.img' ** UNSAFE **

       The solution is to use the --pid-file option to write the guestmount PID to a file, then
       after guestunmount spin waiting for this PID to exit.

        guestmount -a disk.img -i --pid-file guestmount.pid /mnt

        # ...
        # ...

        # Save the PID of guestmount *before* calling guestunmount.
        pid="$(cat guestmount.pid)"

        # Unmount the filesystem.
        guestunmount /mnt

        timeout=10

        count=$timeout
        while kill -0 "$pid" 2>/dev/null && [ $count -gt 0 ]; do
            sleep 1
            ((count--))
        done
        if [ $count -eq 0 ]; then
            echo "$0: wait for guestmount to exit failed after $timeout seconds"
            exit 1
        fi

        # Now it is safe to use the disk image.

       Note that if you use the "guestfs_mount_local" API directly (see "MOUNT LOCAL" in
       guestfs(3)) then it is much easier to write a safe, race-free program.

OPTIONS

       -a image
       --add image
           Add a block device or virtual machine image.

           The format of the disk image is auto-detected.  To override this and force a
           particular format use the --format=.. option.

       -a URI
       --add URI
           Add a remote disk.  See "ADDING REMOTE STORAGE" in guestfish(1).

       -c URI
       --connect URI
           When used in conjunction with the -d option, this specifies the libvirt URI to use.
           The default is to use the default libvirt connection.

       -d libvirt-domain
       --domain libvirt-domain
           Add disks from the named libvirt domain.  If the --ro option is also used, then any
           libvirt domain can be used.  However in write mode, only libvirt domains which are
           shut down can be named here.

           Domain UUIDs can be used instead of names.

       --dir-cache-timeout N
           Set the readdir cache timeout to N seconds, the default being 60 seconds.  The readdir
           cache [actually, there are several semi-independent caches] is populated after a
           readdir(2) call with the stat and extended attributes of the files in the directory,
           in anticipation that they will be requested soon after.

           There is also a different attribute cache implemented by FUSE (see the FUSE option -o
           attr_timeout), but the FUSE cache does not anticipate future requests, only cache
           existing ones.

       --echo-keys
           When prompting for keys and passphrases, guestfish normally turns echoing off so you
           cannot see what you are typing.  If you are not worried about Tempest attacks and
           there is no one else in the room you can specify this flag to see what you are typing.

       --format=raw|qcow2|..
       --format
           The default for the -a option is to auto-detect the format of the disk image.  Using
           this forces the disk format for -a options which follow on the command line.  Using
           --format with no argument switches back to auto-detection for subsequent -a options.

           If you have untrusted raw-format guest disk images, you should use this option to
           specify the disk format.  This avoids a possible security problem with malicious
           guests (CVE-2010-3851).  See also "guestfs_add_drive_opts" in guestfs(3).

       --fuse-help
           Display help on special FUSE options (see -o below).

       --help
           Display brief help and exit.

       -i
       --inspector
           Using virt-inspector(1) code, inspect the disks looking for an operating system and
           mount filesystems as they would be mounted on the real virtual machine.

       --keys-from-stdin
           Read key or passphrase parameters from stdin.  The default is to try to read
           passphrases from the user by opening "/dev/tty".

       --live
           Connect to a live virtual machine.  (Experimental, see "ATTACHING TO RUNNING DAEMONS"
           in guestfs(3)).

       -m dev[:mountpoint[:options[:fstype]]
       --mount dev[:mountpoint[:options[:fstype]]]
           Mount the named partition or logical volume on the given mountpoint in the guest (this
           has nothing to do with mountpoints in the host).

           If the mountpoint is omitted, it defaults to "/".  You have to mount something on "/".

           The third (and rarely used) part of the mount parameter is the list of mount options
           used to mount the underlying filesystem.  If this is not given, then the mount options
           are either the empty string or "ro" (the latter if the --ro flag is used).  By
           specifying the mount options, you override this default choice.  Probably the only
           time you would use this is to enable ACLs and/or extended attributes if the filesystem
           can support them:

            -m /dev/sda1:/:acl,user_xattr

           The fourth part of the parameter is the filesystem driver to use, such as "ext3" or
           "ntfs". This is rarely needed, but can be useful if multiple drivers are valid for a
           filesystem (eg: "ext2" and "ext3"), or if libguestfs misidentifies a filesystem.

       --no-fork
           Don't daemonize (or fork into the background).

       -n
       --no-sync
           By default, we attempt to sync the guest disk when the FUSE mountpoint is unmounted.
           If you specify this option, then we don't attempt to sync the disk.  See the
           discussion of autosync in the guestfs(3) manpage.

       -o option
       --option option
           Pass extra options to FUSE.

           To get a list of all the extra options supported by FUSE, use the command below.  Note
           that only the FUSE -o options can be passed, and only some of them are a good idea.

            guestmount --fuse-help

           Some potentially useful FUSE options:

           -o allow_other
               Allow other users to see the filesystem.

           -o attr_timeout=N
               Enable attribute caching by FUSE, and set the timeout to N seconds.

           -o kernel_cache
               Allow the kernel to cache files (reduces the number of reads that have to go
               through the guestfs(3) API).  This is generally a good idea if you can afford the
               extra memory usage.

           -o uid=N -o gid=N
               Use these options to map all UIDs and GIDs inside the guest filesystem to the
               chosen values.

       --pid-file filename
           Write the PID of the guestmount worker process to "filename".

       -r
       --ro
           Add devices and mount everything read-only.  Also disallow writes and make the disk
           appear read-only to FUSE.

           This is highly recommended if you are not going to edit the guest disk.  If the guest
           is running and this option is not supplied, then there is a strong risk of disk
           corruption in the guest.  We try to prevent this from happening, but it is not always
           possible.

           See also "OPENING DISKS FOR READ AND WRITE" in guestfish(1).

       --selinux
           Enable SELinux support for the guest.

       -v
       --verbose
           Enable verbose messages from underlying libguestfs.

       -V
       --version
           Display the program version and exit.

       -w
       --rw
           This changes the -a, -d and -m options so that disks are added and mounts are done
           read-write.

           See "OPENING DISKS FOR READ AND WRITE" in guestfish(1).

       -x
       --trace
           Trace libguestfs calls and entry into each FUSE function.

           This also stops the daemon from forking into the background (see --no-fork).

FILES

       $HOME/.libguestfs-tools.rc
       /etc/libguestfs-tools.conf
           This configuration file controls the default read-only or read-write mode (--ro or
           --rw).

           See libguestfs-tools.conf(5).

EXIT STATUS

       This program returns 0 if successful, or non-zero if there was an error.

SEE ALSO

       guestunmount(1), fusermount(1), guestfish(1), virt-inspector(1), virt-cat(1),
       virt-edit(1), virt-tar(1), libguestfs-tools.conf(5), "MOUNT LOCAL" in guestfs(3),
       http://libguestfs.org/, http://fuse.sf.net/.

AUTHORS

       Richard W.M. Jones ("rjones at redhat dot com")

COPYRIGHT

       Copyright (C) 2009-2014 Red Hat Inc.

LICENSE

       This program is free software; you can redistribute it and/or modify it under the terms of
       the GNU General Public License as published by the Free Software Foundation; either
       version 2 of the License, or (at your option) any later version.

       This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU General Public License for more details.

       You should have received a copy of the GNU General Public License along with this program;
       if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
       Boston, MA 02110-1301 USA.

BUGS

       To get a list of bugs against libguestfs, use this link:
       https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools

       To report a new bug against libguestfs, use this link:
       https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools

       When reporting a bug, please supply:

       •   The version of libguestfs.

       •   Where you got libguestfs (eg. which Linux distro, compiled from source, etc)

       •   Describe the bug accurately and give a way to reproduce it.

       •   Run libguestfs-test-tool(1) and paste the complete, unedited output into the bug
           report.