2 virt-p2v - P2V (physical to virtual machine) migration tool
8 virt-p2v is a live CD for migrating physical machines to virtual machine
11 In the simplest mode of operation, you take a pre-built live CD ISO from
12 the main website (<http://et.redhat.com/~rjones/virt-p2v/>) and burn it
13 to a CD-R. Then insert the CD-R into the physical machine which must be
14 migrated, reboot, and follow the on-screen instructions. See STANDARD
17 You may also build a customized live CD. Typically this will contain
18 things like server details specific to your organization, so that the
19 live CD can run mostly or completely automatically. See BUILDING A
20 CUSTOM LIVE CD section below.
22 In both cases, files and disk images are transferred from the physical
23 machine over the network to the virtualization host machine over ssh.
24 Therefore "sshd" must be running on the virtualization host, and must be
25 accessible to that host. See SERVER REQUIREMENTS section below.
27 The "virt-p2v" script must only be run from the live CD. It isn't
28 designed to run outside this environment and could do Bad Things to your
29 machine if you try it. The script contains some checks to try to stop
32 Virt-p2v does not modify the physical machine, its disks, configuration
36 After booting the live CD-R, you are presented with a series of
37 questions. This section explains each question.
40 Enter the name or IP address of the virtualization host. This is the
41 host running Xen (or any other virtualization system supported by
42 libvirt, eg. QEMU). This host should be accessible on the network
43 and running an SSH daemon ("sshd").
46 This is the port name or number of the SSH server on the remote
47 host. The default is 22 which is the standard SSH port.
50 Enter the directory on the remote host where disk image(s) and
51 configuration file(s) must reside.
53 Note that if the remote host is running SELinux then you may not be
54 able to start a Xen guest unless its disk image(s) are located in
55 the default directory, "/var/lib/xen/images".
58 Enter the remote SSH username to use to log in to the remote host.
60 If you use the default username of "root" then you should ensure
61 that remote root logins are enabled on the remote host (ie.
62 "PermitRootLogin yes" in "/etc/ssh/sshd_config").
65 Choose the way that the live CD configures network access. The
68 Automatic configuration
69 In this mode, the live CD attempts to reuse the network
70 configuration from the physical machine's root filesystem. You
71 should probably try this method even though occasionally it does
74 Ask for fixed IP address and gateway
75 In this mode the live CD will ask you for a fixed IP address and
76 gateway address, and will configure your chosen interface with
79 Configure from the shell
80 In this mode you will be dropped into a command shell and you
81 will need to issue the correct sequence of "/sbin/ifconfig"
82 commands in order to configure the network interface.
84 A typical sequence of commands which should bring up the network
87 /sbin/ifconfig eth0 AA.BB.CC.DD
88 /sbin/route add default gw GG.HH.II.JJ eth0
90 where "AA.BB.CC.DD" is the IP address and "GG.HH.II.JJ" is the
94 This option configures the network for use inside a QEMU user
96 (<http://fabrice.bellard.free.fr/qemu/qemu-doc.html#SEC30>). It
97 should only be used by developers.
100 This question lists out all local block devices (hard disk drives
101 and similar) and asks you to choose which will be sent to the remote
102 host. You must send at least one block device.
105 This question lists out possible root filesystems and asks you to
106 choose the right one. Choose the filesystem which would normally be
107 mounted as "/" on the system.
109 Virt-p2v performs some autodetection and is in most cases able to
110 work out which filesystems are possible root filesystems. It
111 displays what it thinks is on each filesystem, but leaves it up to
112 the user to make a final decision.
114 The root filesystem is critical because it contains "/etc/fstab".
115 This is used during P2V both to determine how other filesystems are
116 normally mounted on the machine, and because this file and others
117 under "/etc" may need to be modified during P2V conversion.
119 If the machine has more than one root filesystem (typically because
120 the machine is dual-booted with another operating system), then you
121 must choose only one of them to perform the P2V conversion on.
124 This question asks you to choose the hypervisor / virtualization
125 system in use on the remote host.
127 If you select *Xen*, *QEMU* or *KVM* then virt-p2v will produce a
128 configuration file which is customized for the selected system. If
129 you select *Other* then virt-p2v will produce a generic
130 configuration file which will probably require hand-modification to
133 See also <http://libvirt.org/format.html>.
136 This question asks you to choose the machine architecture. Virt-p2v
137 can normally detect this, so you should leave it as *Auto-detect*.
140 This question asks you to choose the amount of memory (RAM) in
141 megabytes assigned to the virtual machine.
143 If the entry is left blank, then virt-p2v will try to autodetect how
144 much RAM is present in the physical machine and use that, and this
145 is probably a good choice for most simple migrations.
148 This question asks you to choose the number of virtual CPUs assigned
149 to the virtual machine. Choosing 1 causes the virtual machine to be
150 uniprocessor, and choosing some number greater than 1 causes the
151 virtual machine to be SMP.
153 If the entry is left blank, then virt-p2v will try to autodetect how
154 many CPU cores are present in the physical machine and use that, and
155 this is probably a good choice for most simple migrations.
158 Here you should enter a MAC address for the virtual machine's
159 emulated network card. MAC addresses are written as
160 "aa:bb:cc:dd:ee:ff" where "aa", "bb" etc are hexadecimal octets.
162 Leaving it blank will cause virt-p2v to choose a random MAC address
163 within the "00:16:3e:.." space reserved for Xen guests. These MAC
164 addresses are not tested for uniqueness so there is a very small
165 chance that they could coincide, which would leave a guest unable to
166 access the virtual network.
169 Choose whether to enable or disable compression on disk images as
170 they are copied across the network.
172 If enabled, the "-C" option is passed to ssh(1). On fast networks
173 this can sometimes be slower.
175 NB: The disk image is still stored uncompressed on the remote host
176 however this option is set.
179 In this step you are asked to verify the settings above. If any are
180 incorrect, use the *Back* button to navigate back to the setting. If
181 all settings are correct, use the *OK* button to begin the P2V
184 Network autoconfiguration
185 If you selected network autoconfiguration above then virt-p2v tries
186 to autoconfigure the network and ping the remote host. It then asks
187 *Did automatic network configuration work?*
189 You should answer "y" here if it worked.
191 Answering "n" will drop you into a command shell.
193 You can also switch to another virtual console if you need to
194 perform additional tests. See section GETTING A SHELL below.
197 Unless you have set up an SSH key, or the SSH server on the remote
198 host allows passwordless logins, then for each file that has to be
199 transferred to the remote host you will need to confirm the identity
200 of the remote host and/or enter a password.
202 To understand more about this, please see the ssh(1) manual page.
204 BOOTING P2V GUEST ON VIRTUALIZATION HOST
205 Once the P2V conversion has been completed, and assuming it was
206 successful, you will find a configuration file and one or more disk
207 images on the remote host.
209 The files will be located in the directory selected, usually
210 "/var/lib/xen/images". The names of the files are made up of:
212 "p2v-*hostname*-*YYYYMMDDHHMM*.conf" or
213 "p2v-*hostname*-*YYYYMMDDHHMM*-hd*X*.img"
215 To simply start up the guest, use the following commands as root:
217 virsh define p2v-foo-2008MMDDHHMM.conf
222 virsh -c qemu:///system define p2v-foo-2008MMDDHHMM.conf
223 virsh -c qemu:///system start foo
225 For other hypervisors you will need to edit the configuration file and
226 read <http://libvirt.org/uri.html>.
229 During all stages of P2V questions and conversion you can get a root
230 shell on the physical machine. Use *ALT* *F2* keys to switch to the
231 second virtual console, then log in as *root* with no password.
234 Virt-p2v writes a detailed log file to "/tmp/virt-p2v.log". (Note that
235 this "/tmp" directory is a ramdisk on the live CD, not the same as the
236 "/tmp" directory of the physical machine, and more importantly it
237 disappears when the machine is rebooted).
239 If you are reporting a bug, please always supply this file.
242 The virtualization host (remote host) must be running an SSH daemon
243 ("sshd"), accessible from the physical machine which is being migrated.
245 Previous versions of virt-p2v could use a special virt-p2v server.
246 However this capability has been removed since there was practically no
249 BUILDING A CUSTOM LIVE CD
250 To build a custom live CD you must download the source for virt-p2v from
251 <http://et.redhat.com/~rjones/virt-p2v/> or from the Mercurial source
252 repository (see website for details).
254 Please read the "README" file to find the dependencies which are all in
255 Fedora > 8 or EPEL > 5.
257 The steps to creating a custom live CD are:
259 1. Edit "virt-p2v" and adjust defaults
260 Find the section "TO MAKE A CUSTOM virt-p2v SCRIPT ..." which is
261 near to the top of this file. Edit the defaults in this section as
264 2. "virt-p2v --test" to verify your changes
265 This command should not print anything at all. If it prints any
266 message, then you will need to fix the error by going back to the
269 3. "make build" or "make update" to build a custom live CD
270 "make build" will create a complete ISO from scratch. "make update"
271 can be used to build a "quick" developer ISO by updating an existing
272 ISO image. See section ISO ATTACHMENTS below for more details.
274 4. Burn the ISO to a CD-R and test
276 EDITING DEFAULTS IN THE "virt-p2v" SCRIPT
277 For each default, setting it to "None" will ask the user. All of the
278 defaults are set to "None" in the standard, uncustomized virt-p2v
279 script, and so the standard script asks all the questions.
281 You may edit "virt-p2v" and change the defaults, in which case the user
282 will not be questioned. In this way you can make the script partially or
285 *Note about OCaml code:* "None" and "Some foo" are similar to the
286 concept of a NULL pointer versus non-NULL pointer in other languages.
287 This a variant type defined as:
289 type α option = None | Some of α
292 If this is "true" then we wait for a keypress after boot and at a
293 couple of other stages. If set to "false" then we try not to wait
294 for any keypresses (so more automated live CDs are possible).
297 Set this to "Some "hostname"" or "Some "IP-address"" to provide the
298 name of the remote host.
301 Set this to "Some port" (eg. "Some 22") to provide the port number
302 of the remote host's SSH daemon.
305 Set this to "Some "path"" (eg. "Some "/var/lib/xen/images"") to
306 provide the directory where we update P2V converted images and
310 Set this to "Some "username"" (eg. "Some "root"") to provide the SSH
311 username to use on the remote system.
314 Set this to a list of block devices to send to the remote system.
315 For example, "Some ["sda"; "sdb"]".
318 Set this to the name of the root filesystem.
320 For a disk partition (eg. "/dev/sda1"), use:
322 Some (Part ("sda", "1"))
324 For a logical volume (eg. "/dev/VolGroup00/LogVol00"), use:
326 Some (LV ("VolGroup00", "LogVol00"))
329 Set this to the choice for network setup. Use one of:
332 for auto-configuration
335 to specify the interface, address, netmask and gateway
342 to use a QEMU user network (developers only)
344 "static_network_config"
345 This setting only applies if "network" is set to "Some Static", in
346 which case you should set this to the static network settings, a
347 tuple of (interface, address, netmask, gateway, nameserver):
349 Some ("eth0", "192.168.2.5", "255.255.255.0", "192.168.2.1", "192.168.2.1")
352 Set this to the choice of hypervisor or virtualization system. The
353 choices are: "Some Xen", "Some QEMU" or "Some KVM".
356 Set this to the architecture. The choices are: "Some I386" (i386 and
357 up, 32 bit), "Some X86_64" (AMD and Intel x86-64, 64 bit), "Some
358 IA64" (Intel IA64), "Some PPC" (PowerPC, 32 bit), "Some PPC64"
359 (PowerPC, 64 bit), "Some SPARC" (Sun SPARC, 32 bit), "Some SPARC64"
360 (Sun SPARC, 64 bit), "OtherArch "foo"" (a hypothetical architecture
361 called *foo*), or "UnknownArch" to auto-detect the architecture.
364 Set this to the size of memory in megabytes, eg. "Some 256". If you
365 set this to "Some 0" then virt-p2v will try to autodetect the amount
366 of RAM installed on the physical machine.
369 Set this to the number of virtual CPUs, eg. "Some 1". If you set
370 this to "Some 0" then virt-p2v will try to autodetect the number of
371 CPU cores on the physical machine.
374 Set this to the MAC address for the virtual network card, eg. "Some
375 "aa:bb:cc:dd:ee:ff"". If you set this to "Some """ then virt-p2v
376 will choose a random MAC address within the "00:16:3e:.." space
377 reserved for Xen guests. These MAC addresses are not tested for
378 uniqueness so there is a very small chance that they could coincide,
379 which would leave a guest unable to access the virtual network.
382 Set this to "Some false" to disable compression, or "Some true" to
383 enable compression, or "None" to ask the user.
386 Rebuilding a custom ISO is time-consuming. You can make a "quick"
387 developer ISO by updating an existing ISO image with a new custom
388 "virt-p2v" script. This is useful for testing purposes.
390 From the source directory, assuming that you have downloaded or built an
391 existing "virt-p2v-*.iso", you can just do:
395 or the equivalent manual command:
397 ./iso-attach virt-p2v-VERSION.iso virt-p2v
399 BOOTING FROM A USB KEY INSTEAD OF A CD
400 If you wish to boot from a USB keydrive, use the livecd-iso-to-disk
403 livecd-iso-to-disk virt-p2v-$VERSION.iso /dev/sdX1
405 (Replace /dev/sdX1 with the actual USB device).
407 In my experience I also had to set up a suitable MBR:
409 cat /usr/lib/syslinux/mbr.bin > /dev/sdX
411 TESTING AN ISO UNDER QEMU OR KVM
412 If you have a virtual guest running under QEMU or KVM then you can test
413 the P2V conversion process on the guest.
415 (Technically this is a V2V -- virtual to virtual -- conversion).
417 From the source directory do:
419 make boot HDA=qemuimage.img
421 where "qemuimage.img" is the name of the QEMU/KVM image.
423 You can also supply an "HDB" parameter to specify a second disk.
426 Please direct questions to the et-mgmt-tools mailing list
427 <http://www.redhat.com/mailman/listinfo/et-mgmt-tools> <et-mgmt-tools @
431 virsh(1), <http://www.libvirt.org/ocaml/>, <http://www.libvirt.org/>,
432 <http://et.redhat.com/~rjones/>, <http://caml.inria.fr/>
435 Richard W.M. Jones <rjones @ redhat . com>
438 (C) Copyright 2007-2008 Red Hat Inc., Richard W.M. Jones
441 This program is free software; you can redistribute it and/or modify it
442 under the terms of the GNU General Public License as published by the
443 Free Software Foundation; either version 2 of the License, or (at your
444 option) any later version.
446 This program is distributed in the hope that it will be useful, but
447 WITHOUT ANY WARRANTY; without even the implied warranty of
448 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
449 Public License for more details.
451 You should have received a copy of the GNU General Public License along
452 with this program; if not, write to the Free Software Foundation, Inc.,
453 675 Mass Ave, Cambridge, MA 02139, USA.
456 Bugs can be viewed on the Red Hat Bugzilla page:
457 <https://bugzilla.redhat.com/>.
459 If you find a bug in virt-p2v, please follow these steps to report it:
461 1. Check for existing bug reports
462 Go to <https://bugzilla.redhat.com/> and search for similar bugs.
463 Someone may already have reported the same bug, and they may even
466 2. Capture debug and error messages
467 At the point where you get the error or unexpected behaviour, go to
468 the second virtual console (*ALT* *F2*) and look at the logfile
469 "/tmp/virt-p2v.log". Please make sure that this file is attached to
472 3. Get version of virt-p2v
473 The version is in the name of the ISO. If you have built a custom
474 virt-p2v ISO, please describe any changes that you have made.
476 4. Submit a bug report.
477 Go to <https://bugzilla.redhat.com/> and enter a new bug. Please
478 describe the problem in as much detail as possible.
480 Remember to include the version number (step 3) and to attach the
483 5. Assign the bug to rjones @ redhat.com
484 Assign or reassign the bug to rjones @ redhat.com (without the
485 spaces). You can also send me an email with the bug number if you
486 want a faster response.