5 guestmount - Mount a guest filesystem on the host using FUSE and libguestfs
9 guestmount [--options] -a disk.img -m device [--ro] mountpoint
11 guestmount [--options] -a disk.img -i [--ro] mountpoint
13 guestmount [--options] -d Guest -i [--ro] mountpoint
17 You must I<not> use C<guestmount> in read-write mode on live virtual
18 machines. If you do this, you risk disk corruption in the VM.
22 The guestmount program can be used to mount virtual machine
23 filesystems and other disk images on the host. It uses libguestfs for
24 access to the guest filesystem, and FUSE (the "filesystem in
25 userspace") to make it appear as a mountable device.
27 Along with other options, you have to give at least one device (I<-a>
28 option) or libvirt domain (I<-d> option), and at least one mountpoint
29 (I<-m> option) or use the I<-i> inspection option or the I<--live>
30 option. How this works is better explained in the L<guestfish(1)>
31 manual page, or by looking at the examples below.
33 FUSE lets you mount filesystems as non-root. The mountpoint must be
34 owned by you, and the filesystem will not be visible to any other
35 users unless you make certain global configuration changes to
36 C</etc/fuse.conf>. To unmount the filesystem, use the C<fusermount -u>
41 For a typical Windows guest which has its main filesystem on the
44 guestmount -a windows.img -m /dev/sda1 --ro /mnt
46 For a typical Linux guest which has a /boot filesystem on the first
47 partition, and the root filesystem on a logical volume:
49 guestmount -a linux.img -m /dev/VG/LV -m /dev/sda1:/boot --ro /mnt
51 To get libguestfs to detect guest mountpoints for you:
53 guestmount -a guest.img -i --ro /mnt
55 For a libvirt guest called "Guest" you could do:
57 guestmount -d Guest -i --ro /mnt
59 If you don't know what filesystems are contained in a guest or
60 disk image, use L<virt-filesystems(1)> first:
62 virt-filesystems MyGuest
64 If you want to trace the libguestfs calls but without excessive
65 debugging information, we recommend:
67 guestmount [...] --trace /mnt
69 If you want to debug the program, we recommend:
71 guestmount [...] --trace --verbose /mnt
75 =head2 Other users cannot see the filesystem by default
77 If you mount a filesystem as one user (eg. root), then other users
78 will not be able to see it by default. The fix is to add the FUSE
79 C<allow_other> option when mounting:
81 sudo guestmount [...] -o allow_other /mnt
85 On some distros, you may need to add yourself to a special group
86 (eg. C<fuse>) before you can use any FUSE filesystem. This is
87 necessary on Debian and derivatives.
89 On other distros, no special group is required. It is not necessary
90 on Fedora or Red Hat Enterprise Linux.
100 Add a block device or virtual machine image.
102 The format of the disk image is auto-detected. To override this and
103 force a particular format use the I<--format=..> option.
107 =item B<--connect URI>
109 When used in conjunction with the I<-d> option, this specifies
110 the libvirt URI to use. The default is to use the default libvirt
113 =item B<-d libvirt-domain>
115 =item B<--domain libvirt-domain>
117 Add disks from the named libvirt domain. If the I<--ro> option is
118 also used, then any libvirt domain can be used. However in write
119 mode, only libvirt domains which are shut down can be named here.
121 Domain UUIDs can be used instead of names.
123 =item B<--dir-cache-timeout N>
125 Set the readdir cache timeout to I<N> seconds, the default being 60
126 seconds. The readdir cache [actually, there are several
127 semi-independent caches] is populated after a readdir(2) call with the
128 stat and extended attributes of the files in the directory, in
129 anticipation that they will be requested soon after.
131 There is also a different attribute cache implemented by FUSE
132 (see the FUSE option I<-o attr_timeout>), but the FUSE cache
133 does not anticipate future requests, only cache existing ones.
137 When prompting for keys and passphrases, guestfish normally turns
138 echoing off so you cannot see what you are typing. If you are not
139 worried about Tempest attacks and there is no one else in the room
140 you can specify this flag to see what you are typing.
142 =item B<--format=raw|qcow2|..>
146 The default for the I<-a> option is to auto-detect the format of the
147 disk image. Using this forces the disk format for I<-a> options which
148 follow on the command line. Using I<--format> with no argument
149 switches back to auto-detection for subsequent I<-a> options.
151 If you have untrusted raw-format guest disk images, you should use
152 this option to specify the disk format. This avoids a possible
153 security problem with malicious guests (CVE-2010-3851). See also
154 L<guestfs(3)/guestfs_add_drive_opts>.
158 Display help on special FUSE options (see I<-o> below).
162 Display brief help and exit.
168 Using L<virt-inspector(1)> code, inspect the disks looking for
169 an operating system and mount filesystems as they would be
170 mounted on the real virtual machine.
172 =item B<--keys-from-stdin>
174 Read key or passphrase parameters from stdin. The default is
175 to try to read passphrases from the user by opening C</dev/tty>.
179 Connect to a live virtual machine.
180 (Experimental, see L<guestfs(3)/ATTACHING TO RUNNING DAEMONS>).
182 =item B<-m dev[:mountpoint[:options]]>
184 =item B<--mount dev[:mountpoint[:options]]>
186 Mount the named partition or logical volume on the given mountpoint
187 B<in the guest> (this has nothing to do with mountpoints in the host).
189 If the mountpoint is omitted, it defaults to C</>. You have to mount
192 The third (and rarely used) part of the mount parameter is the list of
193 mount options used to mount the underlying filesystem. If this is not
194 given, then the mount options are either the empty string or C<ro>
195 (the latter if the I<--ro> flag is used). By specifying the mount
196 options, you override this default choice. Probably the only time you
197 would use this is to enable ACLs and/or extended attributes if the
198 filesystem can support them:
200 -m /dev/sda1:/:acl,user_xattr
206 By default, we attempt to sync the guest disk when the FUSE mountpoint
207 is unmounted. If you specify this option, then we don't attempt to
208 sync the disk. See the discussion of autosync in the L<guestfs(3)>
213 =item B<--option option>
215 Pass extra options to FUSE.
217 To get a list of all the extra options supported by FUSE, use the
218 command below. Note that only the FUSE I<-o> options can be passed,
219 and only some of them are a good idea.
221 guestmount --fuse-help
223 Some potentially useful FUSE options:
227 =item B<-o allow_other>
229 Allow other users to see the filesystem.
231 =item B<-o attr_timeout=N>
233 Enable attribute caching by FUSE, and set the timeout to I<N> seconds.
235 =item B<-o kernel_cache>
237 Allow the kernel to cache files (reduces the number of reads
238 that have to go through the L<guestfs(3)> API). This is generally
239 a good idea if you can afford the extra memory usage.
241 =item B<-o uid=N> B<-o gid=N>
243 Use these options to map all UIDs and GIDs inside the guest filesystem
244 to the chosen values.
252 Add devices and mount everything read-only. Also disallow writes and
253 make the disk appear read-only to FUSE.
255 This is highly recommended if you are not going to edit the guest
256 disk. If the guest is running and this option is I<not> supplied,
257 then there is a strong risk of disk corruption in the guest. We try
258 to prevent this from happening, but it is not always possible.
260 See also L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
264 Enable SELinux support for the guest.
270 Enable verbose messages from underlying libguestfs.
276 Display the program version and exit.
282 This changes the I<-a>, I<-d> and I<-m> options so that disks are
283 added and mounts are done read-write.
285 See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
291 Trace libguestfs calls and entry into each FUSE function.
293 This also stops the daemon from forking into the background.
301 =item $HOME/.libguestfs-tools.rc
303 =item /etc/libguestfs-tools.conf
305 This configuration file controls the default read-only or read-write
306 mode (I<--ro> or I<--rw>).
308 See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
314 This program returns 0 if successful, or non-zero if there was an
320 L<virt-inspector(1)>,
325 L<http://libguestfs.org/>,
326 L<http://fuse.sf.net/>.
330 Richard W.M. Jones (C<rjones at redhat dot com>)
334 Copyright (C) 2009-2010 Red Hat Inc.
335 L<http://libguestfs.org/>
337 This program is free software; you can redistribute it and/or modify
338 it under the terms of the GNU General Public License as published by
339 the Free Software Foundation; either version 2 of the License, or
340 (at your option) any later version.
342 This program is distributed in the hope that it will be useful,
343 but WITHOUT ANY WARRANTY; without even the implied warranty of
344 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
345 GNU General Public License for more details.
347 You should have received a copy of the GNU General Public License
348 along with this program; if not, write to the Free Software
349 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.