1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420
|
=encoding utf8
=begin comment
pod2man and pod2html have differing bugs which makes it hard to write
URLs here. The only way which works for both sorts of output is to
just write the URL directly. Do NOT use L<...> for URLs.
We break with tradition here and don't use ALL CAPS for the section
headings, as this makes them much easier to read.
=end comment
=head1 NAME
guestfs-recipes - libguestfs, guestfish and virt tools recipes
=head1 DESCRIPTION
This page contains recipes for and links to things you can do using
libguestfs, L<guestfish(1)> and the virt tools.
=head1 Audit a virtual machine for setuid files
The link below contains a small program which can be used to audit a
Linux virtual machine to see what setuid and setgid files it contains.
https://rwmj.wordpress.com/2010/12/15/tip-audit-virtual-machine-for-setuid-files/#content
=head1 Change the background image in a Windows XP VM
The links below explain how to use L<guestfish(1)> to change the
background image for a user of a Windows XP VM. Unfortunately the
technique appears to be substantially different for each version of
Windows.
https://lists.fedoraproject.org/pipermail/virt/2011-May/002655.html
https://lists.fedoraproject.org/pipermail/virt/2011-May/002658.html
=head1 Cloning a virtual machine (Linux)
The guestfish technique described in the link below works well for
most Linux VMs. Depending on the Linux distro you may need to change
the paths slightly.
https://rwmj.wordpress.com/2010/09/24/tip-my-procedure-for-cloning-a-fedora-vm/#content
Avoid L<virt-clone(1)>. Currently what to do about virt-clone is
under discussion.
https://www.redhat.com/archives/virt-tools-list/2011-May/msg00019.html
=head1 Cloning a virtual machine (Windows)
It is possible to do a "sysprep" using libguestfs alone, although not
straightforward. Currently there is code in the Aeolus Oz project
which does this (using libguestfs). As part of our review of the
virt-clone tool, we may add sysprepping ability.
https://github.com/clalancette/oz
https://www.redhat.com/archives/virt-tools-list/2011-May/msg00019.html
=head1 Convert a CD-ROM / DVD / ISO to a tarball
This converts input C<cd.iso> to output C<cd.tar.gz>:
guestfish --ro -a cd.iso -m /dev/sda tgz-out / cd.tar.gz
To export just a subdirectory, eg. C</files>, do:
guestfish --ro -a cd.iso -m /dev/sda tgz-out /files cd.tar.gz
=head1 Create empty disk images
You can use the L<guestfish(1)> I<-N> option to create empty disk
images. The useful guide below explains the options available.
https://rwmj.wordpress.com/2010/09/08/new-guestfish-n-options-in-1-5-9/#content
=head1 Dump raw filesystem content from inside a disk image or VM
You can use the L<guestfish(1)> C<download> command to extract the raw
filesystem content from any filesystem in a disk image or a VM (even
one which is encrypted or buried inside an LV):
guestfish --ro -a disk.img run : download /dev/sda1 sda1.img
guestfish --ro -d Guest run : download /dev/vg_guest/lv_root lv.img
To list the filesystems in a disk image, use L<virt-filesystems(1)>.
=head1 Edit grub configuration in a VM
You can use this to:
=over 4
=item *
Fix a virtual machine that does not boot.
=item *
Change which kernel is used to boot the VM.
=item *
Change kernel command line options.
=back
Use L<virt-edit(1)> to edit the grub configuration:
virt-edit -d BrokenGuest /boot/grub/grub.conf
or for general tinkering inside an unbootable VM use L<virt-rescue(1)>
like this:
virt-rescue -d BrokenGuest
=head1 Export any directory from a VM
To export C</home> from a VM into a local directory use
L<virt-copy-out(1)>:
virt-copy-out -d Guest /home .
Notes:
=over 4
=item *
The final dot of the command is not a printing error. It means we
want to copy out to the current directory.
=item *
This creates a directory called C<home> under the current directory.
=back
If the guest is a Windows guest then you can use drive letters and
backslashes, but you must prefix the path with C<win:> and quote it to
protect it from the shell, like this:
virt-copy-out -d WinGuest 'win:c:\windows\system32\config' .
To get the output as a compressed tarball, do:
virt-tar-out -d Guest /home - | gzip --best > home.tar.gz
Although it sounds tempting, this is usually not a reliable way to get
a backup from a running guest. See the entry in the FAQ:
http://libguestfs.org/FAQ.html#backup
=head1 Find out which user is using the most space
This simple script examines a Linux guest to find out which user is
using the most space in their home directory:
#!/bin/sh -
set -e
vm="$1"
dir=/home
eval $(guestfish --ro -d "$vm" -i --listen)
for d in $(guestfish --remote ls "$dir"); do
echo -n "$dir/$d"
echo -ne '\t'
guestfish --remote du "$dir/$d";
done | sort -nr -k 2
guestfish --remote exit
=head1 Get DHCP address from a VM
The link below explains the many different possible techniques for
getting the last assigned DHCP address of a virtual machine.
https://rwmj.wordpress.com/2011/03/31/tip-code-for-getting-dhcp-address-from-a-virtual-machine-disk-image/#content
In the libguestfs source examples directory you will find the latest
version of the C<virt-dhcp-address.c> program.
=head1 Get the operating system product name string
Save the following script into a file called C<product-name.sh>:
#!/bin/sh -
set -e
eval "$(guestfish --ro -d "$1" --i --listen)"
root="$(guestfish --remote inspect-get-roots)"
guestfish --remote inspect-get-product-name "$root"
guestfish --remote exit
Make the script executable and run it on a named guest:
# product-name.sh RHEL60x64
Red Hat Enterprise Linux Server release 6.0 (Santiago)
You can also use an XPath query on the L<virt-inspector(1)> XML using
the C<xpath> command line tool or from your favourite programming
language:
# virt-inspector RHEL60x64 > xml
# xpath '//product_name' < xml
Found 1 nodes:
-- NODE --
<product_name>Red Hat Enterprise Linux Server release 6.0 (Santiago)</product_name>
=head1 Get the default boot kernel for a Linux VM
The link below contains a program to print the default boot kernel for
a Linux VM.
https://rwmj.wordpress.com/2010/10/30/tip-use-augeas-to-get-the-default-boot-kernel-for-a-vm/#content
It uses Augeas, and the technique is generally applicable for many
different tasks, such as:
=over 4
=item *
listing the user accounts in the guest
=item *
what repositories is it configured to use
=item *
what NTP servers does it connect to
=item *
what were the boot messages last time it booted
=item *
listing who was logged in recently
=back
http://augeas.net/
=head1 Install RPMs in a guest
The link below contains a method to install RPMs in a guest. In fact
the RPMs are just uploaded to the guest along with a "firstboot"
script that installs them next time the guest is booted. You could
use this technique to install vital security updates in an offline
guest.
https://rwmj.wordpress.com/2010/12/01/tip-install-rpms-in-a-guest/#content
=head1 List applications installed in a VM
Save the following to a file C<list-apps.sh>:
#!/bin/sh -
set -e
eval "$(guestfish --ro -d "$1" --i --listen)"
root="$(guestfish --remote inspect-get-roots)"
guestfish --remote inspect-list-applications "$root"
guestfish --remote exit
Make the file executable and then you can run it on any named
virtual machine:
# list-apps.sh WinGuest
[0] = {
app_name: Mozilla Firefox (3.6.12)
app_display_name: Mozilla Firefox (3.6.12)
app_epoch: 0
app_version: 3.6.12 (en-GB)
app_release:
app_install_path: C:\Program Files\Mozilla Firefox
app_trans_path:
app_publisher: Mozilla
app_url: http://www.mozilla.com/en-GB/
app_source_package:
app_summary:
app_description: Mozilla Firefox
}
[1] = {
app_name: VLC media player
app_display_name: VLC media player 1.1.5
app_epoch: 0
app_version: 1.1.5
app_release:
app_install_path: C:\Program Files\VideoLAN\VLC
app_trans_path:
app_publisher: VideoLAN
app_url: http://www.videolan.org/
app_source_package:
app_summary:
app_description:
}
If you want to run the script on disk images (instead of libvirt
virtual machines), change C<-d "$1"> to C<-a "$1">. See also
L<virt-inspector(1)>.
=head1 List files and directories in a VM
This involves using the L<guestfish(1)> C<find0> command like this:
guestfish --ro -d Guest -i find0 / - | tr '\0' '\n' | sort
=head1 List services in a Windows VM
The link below contains a script that can be used to list out the
services from a Windows VM, and whether those services run at boot
time or are loaded on demand.
https://rwmj.wordpress.com/2010/12/10/tip-list-services-in-a-windows-guest/#content
=head1 Make a disk image sparse
The link below contains some guides for making a disk image sparse (or
reintroducing sparseness).
https://rwmj.wordpress.com/2010/10/19/tip-making-a-disk-image-sparse/#content
=head1 Monitor disk usage over time
You can use L<virt-df(1)> to monitor disk usage of your guests over
time. The link below contains a guide.
http://virt-tools.org/learning/advanced-virt-df/
=head1 Reading the Windows Event Log from Windows Vista (or later)
L<guestfish(1)> plus the tools described in the link below can be used
to read out the Windows Event Log from any virtual machine running
Windows Vista or a later version.
https://rwmj.wordpress.com/2011/04/17/decoding-the-windows-event-log-using-guestfish/#content
=head1 Remove root password (Linux)
Using the L<virt-edit(1)> I<-e> option you can do simple replacements
on files. One use is to remove the root password from a Linux guest:
virt-edit domname /etc/passwd -e 's/^root:.*?:/root::/'
=head1 Remove Administrator password (Windows)
The link below contains one technique for removing the Administrator
password from a Windows VM, or to be more precise, it gives you a
command prompt the next time you log in which you can use to bypass
any security:
https://mdbooth.wordpress.com/2010/10/18/resetting-a-windows-guests-administrator-password-with-guestfish/
=head1 Unpack a live CD
Linux live CDs often contain multiple layers of disk images wrapped
like a Russian doll. You can use L<guestfish(1)> to look inside these
multiple layers, as outlined in the guide below.
https://rwmj.wordpress.com/2009/07/15/unpack-the-russian-doll-of-a-f11-live-cd/#content
=head1 Uploading and downloading files
The link below contains general tips on uploading (copying in)
and downloading (copying out) files from VMs.
https://rwmj.wordpress.com/2010/12/02/tip-uploading-and-downloading/#content
=head1 Use libguestfs tools on VMware ESX guests
The link below explains how to use libguestfs, L<guestfish(1)> and the
virt tools on any VMware ESX guests, by first sharing the VMware VMFS
over sshfs.
https://rwmj.wordpress.com/2011/05/10/tip-use-libguestfs-on-vmware-esx-guests/#content
=head1 SEE ALSO
L<guestfs(3)>,
L<guestfish(1)>,
L<guestfs-examples(3)>,
L<guestfs-erlang(3)>,
L<guestfs-java(3)>,
L<guestfs-ocaml(3)>,
L<guestfs-perl(3)>,
L<guestfs-python(3)>,
L<guestfs-ruby(3)>,
L<http://libguestfs.org/>.
=head1 AUTHORS
Richard W.M. Jones (C<rjones at redhat dot com>)
=head1 COPYRIGHT
Copyright (C) 2009-2012 Red Hat Inc. L<http://libguestfs.org/>
The examples in this manual page may be freely copied, modified and
distributed without any restrictions.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|