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-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
87 =item B<-a image> | B<--add image>
89 Add a block device or virtual machine image.
91 The format of the disk image is auto-detected. To override this and
92 force a particular format use the I<--format=..> option.
94 =item B<-c URI> | B<--connect URI>
96 When used in conjunction with the I<-d> option, this specifies
97 the libvirt URI to use. The default is to use the default libvirt
100 =item B<-d libvirt-domain> | B<--domain libvirt-domain>
102 Add disks from the named libvirt domain. If the I<--ro> option is
103 also used, then any libvirt domain can be used. However in write
104 mode, only libvirt domains which are shut down can be named here.
106 Domain UUIDs can be used instead of names.
108 =item B<--dir-cache-timeout N>
110 Set the readdir cache timeout to I<N> seconds, the default being 60
111 seconds. The readdir cache [actually, there are several
112 semi-independent caches] is populated after a readdir(2) call with the
113 stat and extended attributes of the files in the directory, in
114 anticipation that they will be requested soon after.
116 There is also a different attribute cache implemented by FUSE
117 (see the FUSE option I<-o attr_timeout>), but the FUSE cache
118 does not anticipate future requests, only cache existing ones.
122 When prompting for keys and passphrases, guestfish normally turns
123 echoing off so you cannot see what you are typing. If you are not
124 worried about Tempest attacks and there is no one else in the room
125 you can specify this flag to see what you are typing.
127 =item B<--format=raw|qcow2|..> | B<--format>
129 The default for the I<-a> option is to auto-detect the format of the
130 disk image. Using this forces the disk format for I<-a> options which
131 follow on the command line. Using I<--format> with no argument
132 switches back to auto-detection for subsequent I<-a> options.
134 If you have untrusted raw-format guest disk images, you should use
135 this option to specify the disk format. This avoids a possible
136 security problem with malicious guests (CVE-2010-3851). See also
137 L<guestfs(3)/guestfs_add_drive_opts>.
141 Display help on special FUSE options (see I<-o> below).
145 Display brief help and exit.
147 =item B<-i> | B<--inspector>
149 Using L<virt-inspector(1)> code, inspect the disks looking for
150 an operating system and mount filesystems as they would be
151 mounted on the real virtual machine.
153 =item B<--keys-from-stdin>
155 Read key or passphrase parameters from stdin. The default is
156 to try to read passphrases from the user by opening C</dev/tty>.
160 Connect to a live virtual machine.
161 (Experimental, see L<guestfs(3)/ATTACHING TO RUNNING DAEMONS>).
163 =item B<-m dev[:mountpoint[:options]]>
165 =item B<--mount dev[:mountpoint[:options]]>
167 Mount the named partition or logical volume on the given mountpoint
168 B<in the guest> (this has nothing to do with mountpoints in the host).
170 If the mountpoint is omitted, it defaults to C</>. You have to mount
173 The third (and rarely used) part of the mount parameter is the list of
174 mount options used to mount the underlying filesystem. If this is not
175 given, then the mount options are either the empty string or C<ro>
176 (the latter if the I<--ro> flag is used). By specifying the mount
177 options, you override this default choice. Probably the only time you
178 would use this is to enable ACLs and/or extended attributes if the
179 filesystem can support them:
181 -m /dev/sda1:/:acl,user_xattr
183 =item B<-n> | B<--no-sync>
185 By default, we attempt to sync the guest disk when the FUSE mountpoint
186 is unmounted. If you specify this option, then we don't attempt to
187 sync the disk. See the discussion of autosync in the L<guestfs(3)>
190 =item B<-o option> | B<--option option>
192 Pass extra options to FUSE.
194 To get a list of all the extra options supported by FUSE, use the
195 command below. Note that only the FUSE I<-o> options can be passed,
196 and only some of them are a good idea.
198 guestmount --fuse-help
200 Some potentially useful FUSE options:
204 =item B<-o allow_other>
206 Allow other users to see the filesystem.
208 =item B<-o attr_timeout=N>
210 Enable attribute caching by FUSE, and set the timeout to I<N> seconds.
212 =item B<-o kernel_cache>
214 Allow the kernel to cache files (reduces the number of reads
215 that have to go through the L<guestfs(3)> API). This is generally
216 a good idea if you can afford the extra memory usage.
218 =item B<-o uid=N> B<-o gid=N>
220 Use these options to map all UIDs and GIDs inside the guest filesystem
221 to the chosen values.
225 =item B<-r> | B<--ro>
227 Add devices and mount everything read-only. Also disallow writes and
228 make the disk appear read-only to FUSE.
230 This is highly recommended if you are not going to edit the guest
231 disk. If the guest is running and this option is I<not> supplied,
232 then there is a strong risk of disk corruption in the guest. We try
233 to prevent this from happening, but it is not always possible.
235 See also L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
239 Enable SELinux support for the guest.
241 =item B<-v> | B<--verbose>
243 Enable verbose messages from underlying libguestfs.
245 =item B<-V> | B<--version>
247 Display the program version and exit.
249 =item B<-w> | B<--rw>
251 This changes the I<-a>, I<-d> and I<-m> options so that disks are
252 added and mounts are done read-write.
254 See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
256 =item B<-x> | B<--trace>
258 Trace libguestfs calls and entry into each FUSE function.
260 This also stops the daemon from forking into the background.
268 =item $HOME/.libguestfs-tools.rc
270 =item /etc/libguestfs-tools.conf
272 This configuration file controls the default read-only or read-write
273 mode (I<--ro> or I<--rw>).
275 See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.
282 L<virt-inspector(1)>,
287 L<http://libguestfs.org/>,
288 L<http://fuse.sf.net/>.
292 Richard W.M. Jones (C<rjones at redhat dot com>)
296 Copyright (C) 2009-2010 Red Hat Inc.
297 L<http://libguestfs.org/>
299 This program is free software; you can redistribute it and/or modify
300 it under the terms of the GNU General Public License as published by
301 the Free Software Foundation; either version 2 of the License, or
302 (at your option) any later version.
304 This program is distributed in the hope that it will be useful,
305 but WITHOUT ANY WARRANTY; without even the implied warranty of
306 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
307 GNU General Public License for more details.
309 You should have received a copy of the GNU General Public License
310 along with this program; if not, write to the Free Software
311 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.