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. How this works is
30 better explained in the L<guestfish(1)> manual page, or by looking at
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-list-filesystems(1)> first:
62 virt-list-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
77 =item B<-a image> | B<--add image>
79 Add a block device or virtual machine image.
81 The format of the disk image is auto-detected. To override this and
82 force a particular format use the I<--format=..> option.
84 =item B<-c URI> | B<--connect URI>
86 When used in conjunction with the I<-d> option, this specifies
87 the libvirt URI to use. The default is to use the default libvirt
90 =item B<-d libvirt-domain> | B<--domain libvirt-domain>
92 Add disks from the named libvirt domain. If the I<--ro> option is
93 also used, then any libvirt domain can be used. However in write
94 mode, only libvirt domains which are shut down can be named here.
96 =item B<--dir-cache-timeout N>
98 Set the readdir cache timeout to I<N> seconds, the default being 60
99 seconds. The readdir cache [actually, there are several
100 semi-independent caches] is populated after a readdir(2) call with the
101 stat and extended attributes of the files in the directory, in
102 anticipation that they will be requested soon after.
104 There is also a different attribute cache implemented by FUSE
105 (see the FUSE option I<-o attr_timeout>), but the FUSE cache
106 does not anticipate future requests, only cache existing ones.
108 =item B<--format=raw|qcow2|..> | B<--format>
110 The default for the I<-a> option is to auto-detect the format of the
111 disk image. Using this forces the disk format for I<-a> options which
112 follow on the command line. Using I<--format> with no argument
113 switches back to auto-detection for subsequent I<-a> options.
115 If you have untrusted raw-format guest disk images, you should use
116 this option to specify the disk format. This avoids a possible
117 security problem with malicious guests (CVE-2010-3851). See also
118 L<guestfs(3)/guestfs_add_drive_opts>.
122 Display help on special FUSE options (see I<-o> below).
126 Display brief help and exit.
128 =item B<-i> | B<--inspector>
130 Using L<virt-inspector(1)> code, inspect the disks looking for
131 an operating system and mount filesystems as they would be
132 mounted on the real virtual machine.
134 =item B<-m dev[:mnt]> | B<--mount dev[:mnt]>
136 Mount the named partition or logical volume on the given mountpoint
137 B<in the guest> (this has nothing to do with mountpoints in the host).
139 If the mountpoint is omitted, it defaults to C</>. You have to mount
142 =item B<-n> | B<--no-sync>
144 By default, we attempt to sync the guest disk when the FUSE mountpoint
145 is unmounted. If you specify this option, then we don't attempt to
146 sync the disk. See the discussion of autosync in the L<guestfs(3)>
149 =item B<-o option> | B<--option option>
151 Pass extra options to FUSE.
153 To get a list of all the extra options supported by FUSE, use the
154 command below. Note that only the FUSE I<-o> options can be passed,
155 and only some of them are a good idea.
157 guestmount --fuse-help
159 Some potentially useful FUSE options:
163 =item B<-o allow_other>
165 Allow other users to see the filesystem.
167 =item B<-o attr_timeout=N>
169 Enable attribute caching by FUSE, and set the timeout to I<N> seconds.
171 =item B<-o kernel_cache>
173 Allow the kernel to cache files (reduces the number of reads
174 that have to go through the L<guestfs(3)> API). This is generally
175 a good idea if you can afford the extra memory usage.
177 =item B<-o uid=N> B<-o gid=N>
179 Use these options to map all UIDs and GIDs inside the guest filesystem
180 to the chosen values.
184 =item B<-r> | B<--ro>
186 Add devices and mount everything read-only. Also disallow writes and
187 make the disk appear read-only to FUSE.
189 This is highly recommended if you are not going to edit the guest
190 disk. If the guest is running and this option is I<not> supplied,
191 then there is a strong risk of disk corruption in the guest. We try
192 to prevent this from happening, but it is not always possible.
196 Enable SELinux support for the guest.
198 =item B<-v> | B<--verbose>
200 Enable verbose messages from underlying libguestfs.
202 =item B<-V> | B<--version>
204 Display the program version and exit.
206 =item B<-x> | B<--trace>
208 Trace libguestfs calls.
210 This also stops the daemon from forking into the background.
217 L<virt-inspector(1)>,
222 L<http://libguestfs.org/>,
223 L<http://fuse.sf.net/>.
227 Richard W.M. Jones (C<rjones at redhat dot com>)
231 Copyright (C) 2009-2010 Red Hat Inc.
232 L<http://libguestfs.org/>
234 This program is free software; you can redistribute it and/or modify
235 it under the terms of the GNU General Public License as published by
236 the Free Software Foundation; either version 2 of the License, or
237 (at your option) any later version.
239 This program is distributed in the hope that it will be useful,
240 but WITHOUT ANY WARRANTY; without even the implied warranty of
241 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
242 GNU General Public License for more details.
244 You should have received a copy of the GNU General Public License
245 along with this program; if not, write to the Free Software
246 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.