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