1virt-p2v(1) Virtualization Support virt-p2v(1)
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6 virt-p2v - Convert a physical machine to use KVM
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9 virt-p2v
10 virt-p2v.iso
12
14 Virt-p2v converts a physical machine to run virtualized on KVM, managed
15 by libvirt, OpenStack, oVirt, Red Hat Virtualisation (RHV), or one of
16 the other targets supported by virt-v2v(1).
17 Normally you don’t run the virt-p2v program directly. Instead you have
19 to boot the physical machine using the bootable CD-ROM, ISO or PXE
20 image. This bootable image contains the virt-p2v binary and runs it
21 automatically. Booting from a CD-ROM/etc is required because the disks
22 which are being converted must be quiescent. It is not safe to try to
23 convert a running physical machine where other programs may be
24 modifying the disk content at the same time.
25 This manual page documents running the virt-p2v program. To create the
27 bootable image you should look at virt-p2v-make-disk(1) or
28 virt-p2v-make-kickstart(1).
29
31 Virt-p2v runs on the physical machine which you want to convert. It
32 has to talk to another server called the "conversion server" which must
33 have virt-v2v(1) installed on it. It always talks to the conversion
34 server over SSH:
35 ┌──────────────┐ ┌─────────────────┐
37 │ virt-p2v │ │ virt-v2v │
38 │ (physical │ ssh connection │ (conversion │
39 │ server) ╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍▶ server) │
40 └──────────────┘ └─────────────────┘
41 The virt-v2v program on the conversion server does the actual
43 conversion (physical to virtual, and virtual to virtual conversions are
44 sufficiently similar that we use the same program to do both).
45 The SSH connection is always initiated from the physical server. All
47 data is transferred over the SSH connection. In terms of firewall and
48 network configuration, you only need to ensure that the physical server
49 has access to a port (usually TCP port 22) on the conversion server.
50 Note that the physical machine may reconnect several times during the
51 conversion process.
52 The reverse port forwarding feature of ssh (ie. "ssh -R") is required
54 by virt-p2v, and it will not work if this is disabled on the conversion
55 server. ("AllowTcpForwarding" must be "yes" in the sshd_config(5) file
56 on the conversion server).
57 The scp (secure copy) feature of ssh is required by virt-p2v so it can
59 send over small files (this is not the method by which disks are
60 copied).
61 The conversion server does not need to be a physical machine. It could
63 be a virtual machine, as long as it has sufficient memory and disk
64 space to do the conversion, and as long as the physical machine can
65 connect directly to its SSH port. (See also "Resource requirements" in
66 virt-v2v(1)).
67 Because all of the data on the physical server’s hard drive(s) has to
69 be copied over the network, the speed of conversion is largely
70 determined by the speed of the network between the two machines.
71
73 When you start virt-p2v, you'll see a graphical configuration dialog
74 that walks you through connection to the conversion server, asks for
75 the password, which local hard disks you want to convert, and other
76 things like the name of the guest to create and the number of virtual
77 CPUs to give it.
78 SSH CONFIGURATION DIALOG
80 When virt-p2v starts up in GUI mode, the first dialog looks like this:
81 ┌─────────────────────────────────────────────────────────────┐
83 │ virt-p2v │
84 │ │
85 │ Conversion server: [____________________________] : [22___] │
86 │ │
87 │ User name: [root__________________________________] │
88 │ │
89 │ Password: [______________________________________] │
90 │ │
91 │ SSH Identity URL: [______________________________________] │
92 │ │
93 In the fields above, you must enter the details of the conversion
95 server: the hostname, SSH port number, remote user name, and either the
96 password or SSH identity (private key) URL. The conversion server must
97 have an up to date version of virt-v2v.
98 Normally you must log in to the conversion server as root, but if you
100 check the following box:
101 │ │
103 │ [ ] Use sudo when running virt-v2v │
104 │ │
105 then you can log in as another user, and virt-p2v will use the sudo(8)
107 command to elevate privileges to root. Note that sudo must not require
108 a password.
109 It is also possible to run virt-v2v on the conversion server entirely
111 as non-root, but output modes may be limited. Consult the virt-v2v(1)
112 manual page for details.
113 At the bottom of the dialog are these buttons:
115 │ │
117 │ [ Test connection ] │
118 │ │
119 │ [ Configure network ] [ XTerm ] [ About virt-p2v ] [ Next ] │
120 │ │
121 └─────────────────────────────────────────────────────────────┘
122 You must press the "Test connection" button first to test the SSH
124 connection to the conversion server. If that is successful (ie. you
125 have supplied the correct server name, user name, password, etc., and a
126 suitable version of virt-v2v is available remotely) then press the
127 "Next" button to move to the next dialog.
128 You can use the "Configure network" button if you need to assign a
130 static IP address to the physical machine, or use Wifi, bonding or
131 other network features.
132 The "XTerm" button opens a shell which can be used for diagnostics,
134 manual network configuration, and so on.
135 DISK AND NETWORK CONFIGURATION DIALOG
137 The second configuration dialog lets you configure the details of
138 conversion, including what to convert and where to send the guest.
139 In the left hand column, starting at the top, the target properties let
141 you select the name of the guest (ie. after conversion) and how many
142 virtual CPUs and how much RAM to give it. The defaults come from the
143 physical machine, and you can usually leave them unchanged:
144 ┌─────────────────────────────────────── ─ ─ ─ ─
146 │ Target properties:
147 │
148 │ Name: [hostname______________]
149 │
150 │ # vCPUs: [4_____________________]
151 │
152 │ Memory (MB): [16384_________________]
153 │
154 The second panel on the left controls the virt-v2v output options. To
156 understand these options it is a really good idea to read the
157 virt-v2v(1) manual page. You can leave the options at the default to
158 create a guest as a disk image plus libvirt XML file located in
159 /var/tmp on the conversion host. This is a good idea if you are a
160 first-time virt-p2v user.
161 │
163 │ Virt-v2v output options:
164 │
165 │ Output to (-o): [local ▼]
166 │
167 │ Output conn. (-oc): [___________________]
168 │
169 │ Output storage (-os): [/var/tmp___________]
170 │
171 │ Output format (-of): [___________________]
172 │
173 │ Output allocation (-oa): [sparse ▼]
174 │
175 All output options and paths are relative to the conversion server (not
177 to the physical server).
178 Finally in the left hand column is an information box giving the
180 version of virt-p2v (on the physical server) and virt-v2v (on the
181 conversion server). You should supply this information when reporting
182 bugs.
183 In the right hand column are three panels which control what hard
185 disks, removable media devices, and network interfaces, will be created
186 in the output guest. Normally leaving these at the default settings is
187 fine.
188 ─ ─ ──────────────────────────────────────────────────┐
190 Fixed hard disks │
191 │
192 Convert Device │
193 [✔] sda │
194 1024G HITACHI │
195 s/n 12345 │
196 [✔] sdb │
197 119G HITACHI │
198 s/n 12346 │
199 │
200 Normally you would want to convert all hard disks. If you want
202 virt-p2v to completely ignore a local hard disk, uncheck it. The hard
203 disk that contains the operating system must be selected. If a hard
204 disk is part of a RAID array or LVM volume group (VG), then either all
205 hard disks in that array/VG must be selected, or none of them.
206 │
208 Removable media │
209 │
210 Convert Device │
211 [✔] sr0 │
212 │
213 If the physical machine has CD or DVD drives, then you can use the
215 Removable media panel to create corresponding drives on the guest after
216 conversion. Note that any data CDs/DVDs which are mounted in the
217 drives are not copied over.
218 At the bottom of the dialog, the "Refresh disks" button instructs
220 virt-p2v to re-enumerate the fixed hard disks and the removable media
221 drives. (Note that the button will also reset the currently active
222 selections in both of those panels.) This button is useful in
223 combination with the "XTerm" button on the "SSH CONFIGURATION DIALOG":
224 in the XTerm window, you can expose further block devices to the kernel
225 (such as LUNs from iSCSI targets), and the "Refresh disks" button
226 allows virt-p2v to learn about all the block devices again.
227 │
229 Network interfaces │
230 │
231 Convert Device Connect to virtual network │
232 [✔] em1 [default________________________] │
233 [ ] wlp3s0 [default________________________] │
234 │
235 In the Network interfaces panel, select the network interfaces that
237 should be created in the guest after conversion. You can also connect
238 these to target hypervisor networks (for further information about this
239 feature, see "Networks and bridges" in virt-v2v(1)).
240 On supported hardware, left-clicking on the device name (eg. "em1")
242 causes a light to start flashing on the physical interface, allowing
243 the interface to be identified by the operator.
244 When you are ready to begin the conversion, press the "Start
246 conversion" button:
247 │
249 [ Back ] [ Refresh disks ] [ Start conversion ] │
250 │
251 ─ ─ ──────────────────────────────────────────────────┘
252 CONVERSION RUNNING DIALOG
254 When conversion is running you will see this dialog:
255 ┌────────────────────────────────────────────────────────┐
257 │ virt-p2v │
258 │ │
259 │ ┌──────────────────────────────────────────────────┐ │
260 │ │ ▲│ │
261 │ │ │ │
262 │ │ │ │
263 ∼ ∼ ∼ ∼
264 │ │ │ │
265 │ │ │ │
266 │ │ ▼│ │
267 │ └──────────────────────────────────────────────────┘ │
268 │ │
269 │ Log files ... to /tmp/virt-p2v-xxx │
270 │ │
271 │ Doing conversion ... │
272 │ │
273 │ [ Cancel conversion ] │
274 │ │
275 └────────────────────────────────────────────────────────┘
276 In the main scrolling area you will see messages from the virt-v2v
278 process.
279 Below the main area, virt-p2v shows you the location of the directory
281 on the conversion server that contains log files and other debugging
282 information. Below that is the current status and a button for
283 cancelling conversion.
284 Once conversion has finished, you should shut down the physical
286 machine. If conversion is successful, you should never reboot it.
287
289 If you don’t want to configure things using the graphical UI, an
290 alternative is to configure through the kernel command line. This is
291 especially convenient if you are converting a lot of physical machines
292 which are booted using PXE.
293 Where exactly you set command line arguments depends on your PXE
295 implementation, but for pxelinux you put them in the "APPEND" field in
296 the pxelinux.cfg file. For example:
297 DEFAULT p2v
299 TIMEOUT 20
300 PROMPT 0
301 LABEL p2v
302 KERNEL vmlinuz0
303 APPEND initrd=initrd0.img [....] p2v.server=conv.example.com p2v.password=secret p2v.o=libvirt
304 You have to set some or all of the following command line arguments:
306 p2v.remote.server=SERVER
308 p2v.server=SERVER
309 The name or IP address of the conversion server.
310 This is always required if you are using the kernel configuration
312 method. If virt-p2v does not find this on the kernel command line
313 then it switches to the GUI (interactive) configuration method.
314 p2v.remote.port=PORT
316 p2v.port=PORT
317 The SSH port number on the conversion server (default: 22).
318 p2v.auth.username=USERNAME
320 p2v.username=USERNAME
321 The SSH username that we log in as on the conversion server
322 (default: "root").
323 p2v.auth.password=PASSWORD
325 p2v.password=PASSWORD
326 The SSH password that we use to log in to the conversion server.
327 The default is to try with no password. If this fails then
329 virt-p2v will ask the user to type the password (probably several
330 times during conversion).
331 This setting is ignored if "p2v.auth.identity.url" is present.
333 p2v.auth.identity.url=URL
335 p2v.identity=URL
336 Provide a URL pointing to an SSH identity (private key) file. The
337 URL is interpreted by curl(1) so any URL that curl supports can be
338 used here, including "https://" and "file://". For more
339 information on using SSH identities, see "SSH IDENTITIES" below.
340 If "p2v.auth.identity.url" is present, it overrides
342 "p2v.auth.password". There is no fallback.
343 p2v.auth.sudo
345 p2v.sudo
346 Use "p2v.sudo" to tell virt-p2v to use sudo(8) to gain root
347 privileges on the conversion server after logging in as a non-root
348 user (default: do not use sudo).
349 p2v.guestname=GUESTNAME
351 p2v.name=GUESTNAME
352 The name of the guest that is created. The default is to try to
353 derive a name from the physical machine’s hostname (if possible)
354 else use a randomly generated name.
355 p2v.vcpu.phys_topo
357 Copy the physical machine's complete CPU topology (sockets, cores
358 and threads) to the guest. Disabled by default. If disabled, the
359 "p2v.vcpu.cores" setting takes effect.
360 p2v.vcpu.cores=N
362 This setting is ignored if "p2v.vcpu.phys_topo" is enabled.
363 Otherwise, it specifies the flat number of vCPU cores to give to
364 the guest (placing all of those cores into a single socket, and
365 exposing one thread per core). The default value is the number of
366 online logical processors on the physical machine.
367 p2v.memory=n(M|G)
369 The size of the guest memory. You must specify the unit such as
370 megabytes or gigabytes by using for example "p2v.memory=1024M" or
371 "p2v.memory=1G".
372 The default is to use the same amount of RAM as on the physical
374 machine.
375 p2v.cpu.vendor=VENDOR
377 The vCPU vendor, eg. "Intel" or "AMD". The default is to use the
378 same CPU vendor as the physical machine.
379 p2v.cpu.model=MODEL
381 The vCPU model, eg. "IvyBridge". The default is to use the same
382 CPU model as the physical machine.
383 p2v.cpu.acpi
385 Whether to enable ACPI in the remote virtual machine. The default
386 is to use the same as the physical machine.
387 p2v.cpu.apic
389 Whether to enable APIC in the remote virtual machine. The default
390 is to use the same as the physical machine.
391 p2v.cpu.pae
393 Whether to enable PAE in the remote virtual machine. The default
394 is to use the same as the physical machine.
395 p2v.rtc.basis=(unknown|utc|localtime)
397 Set the basis of the Real Time Clock in the virtual machine. The
398 default is to try to detect this setting from the physical machine.
399 p2v.rtc.offset=[+|-]HOURS
401 The offset of the Real Time Clock from UTC. The default is to try
402 to detect this setting from the physical machine.
403 p2v.disks=sda,sdb,...
405 A list of physical hard disks to convert, for example:
406 p2v.disks=sda,sdc
408 The default is to convert all local hard disks that are found.
410 p2v.removable=sra,srb,...
412 A list of removable media to convert. The default is to create
413 virtual removable devices for every physical removable device
414 found. Note that the content of removable media is never copied
415 over.
416 p2v.interfaces=em1,...
418 A list of network interfaces to convert. The default is to create
419 virtual network interfaces for every physical network interface
420 found.
421 p2v.network_map=interface:target,...
423 p2v.network=interface:target,...
424 Controls how network interfaces are connected to virtual networks
425 on the target hypervisor. The default is to connect all network
426 interfaces to the target "default" network.
427 You give a comma-separated list of "interface:target" pairs, plus
429 optionally a default target. For example:
430 p2v.network=em1:ovirtmgmt
432 maps interface "em1" to target network "ovirtmgmt".
434 p2v.network=em1:ovirtmgmt,em2:management,other
436 maps interface "em1" to "ovirtmgmt", and "em2" to "management", and
438 any other interface that is found to "other".
439 p2v.output.type=(libvirt|local|...)
441 p2v.o=(libvirt|local|...)
442 Set the output mode. This is the same as the virt-v2v -o option.
443 See "OPTIONS" in virt-v2v(1).
444 If not specified, the default is "local", and the converted guest
446 is written to /var/tmp.
447 p2v.output.allocation=(none|sparse|preallocated)
449 p2v.oa=(none|sparse|preallocated)
450 Set the output allocation mode. This is the same as the virt-v2v
451 -oa option. See "OPTIONS" in virt-v2v(1).
452 p2v.output.connection=URI
454 p2v.oc=URI
455 Set the output connection libvirt URI. This is the same as the
456 virt-v2v -oc option. See "OPTIONS" in virt-v2v(1) and
457 http://libvirt.org/uri.html
458 p2v.output.format=(raw|qcow2|...)
460 p2v.of=(raw|qcow2|...)
461 Set the output format. This is the same as the virt-v2v -of
462 option. See "OPTIONS" in virt-v2v(1).
463 p2v.output.storage=STORAGE
465 p2v.os=STORAGE
466 Set the output storage. This is the same as the virt-v2v -os
467 option. See "OPTIONS" in virt-v2v(1).
468 If not specified, the default is /var/tmp (on the conversion
470 server).
471 p2v.pre=COMMAND
473 p2v.pre="COMMAND ARG ..."
474 Select a pre-conversion command to run. Any command or script can
475 be specified here. If the command contains spaces, you must quote
476 the whole command with double quotes. The default is not to run
477 any command.
478 p2v.post=poweroff
480 p2v.post=reboot
481 p2v.post=COMMAND
482 p2v.post="COMMAND ARG ..."
483 Select a post-conversion command to run if conversion is
484 successful. This can be any command or script. If the command
485 contains spaces, you must quote the whole command with double
486 quotes.
487 If virt-p2v is running as root, and the command line was set from
489 /proc/cmdline (not --cmdline), then the default is to run the
490 poweroff(8) command. Otherwise the default is not to run any
491 command.
492 p2v.fail=COMMAND
494 p2v.fail="COMMAND ARG ..."
495 Select a post-conversion command to run if conversion fails. Any
496 command or script can be specified here. If the command contains
497 spaces, you must quote the whole command with double quotes. The
498 default is not to run any command.
499 ip=dhcp
501 Use DHCP for configuring the network interface (this is the
502 default).
503
505 As a somewhat more secure alternative to password authentication, you
506 can use an SSH identity (private key) for authentication.
507 First create a key pair. It must have an empty passphrase:
509 ssh-keygen -t rsa -N '' -f id_rsa
511 This creates a private key ("id_rsa") and a public key ("id_rsa.pub")
513 pair.
514 The public key should be appended to the "authorized_keys" file on the
516 virt-v2v conversion server (usually to "/root/.ssh/authorized_keys").
517 For distributing the private key, there are four scenarios from least
519 secure to most secure:
520 1. Not using SSH identities at all, ie. password authentication.
522 Anyone who can sniff the PXE boot parameters from the network or
524 observe the password some other way can log in to the virt-v2v
525 conversion server.
526 2. SSH identity embedded in the virt-p2v ISO or disk image. In the
528 GUI, use:
529 │ Password: [ <leave this field blank> ] │
531 │ │
532 │ SSH Identity URL: [file:///var/tmp/id_rsa_____________] │
533 or on the kernel command line:
535 p2v.identity=file:///var/tmp/id_rsa
537 The SSH private key can still be sniffed from the network if using
539 standard PXE.
540 3. SSH identity downloaded from a website. In the GUI, use:
542 │ Password: [ <leave this field blank> ] │
544 │ │
545 │ SSH Identity URL: [https://internal.example.com/id_rsa] │
546 or on the kernel command line:
548 p2v.identity=https://internal.example.com/id_rsa
550 Anyone could still download the private key and use it to log in to
552 the virt-v2v conversion server, but you could provide some extra
553 security by configuring the web server to only allow connections
554 from P2V machines.
555 Note that ssh-keygen(1) creates the "id_rsa" (private key) file
557 with mode 0600. If you simply copy the file to a webserver, the
558 webserver will not serve it. It will reply with "403 Forbidden"
559 errors. You will need to change the mode of the file to make it
560 publicly readable, for example by using:
561 chmod 0644 id_rsa
563 4. SSH identity embedded in the virt-p2v ISO or disk image (like 2.),
565 and use of secure PXE, PXE over separate physical network, or
566 sneakernet to distribute virt-p2v to the physical machine.
567 Both virt-p2v-make-disk(1) and virt-p2v-make-kickstart(1) have the same
569 option --inject-ssh-identity for injecting the private key into the
570 virt-p2v disk image / ISO. See also the following manual sections:
571 "ADDING AN SSH IDENTITY" in virt-p2v-make-disk(1)
573 "ADDING AN SSH IDENTITY" in virt-p2v-make-kickstart(1)
575
577 In case the disk that contains the operating system, or other disks
578 that you want to convert, are LUNs of remote iSCSI targets, follow the
579 steps below so that virt-p2v can learn about said disks. Note that
580 this procedure depends on the use of the GUI.
581 The guide below is roughly based on the RHEL9 product documentation.
583 1. Open a shell in an XTerm window, using the "XTerm" button of the
585 "SSH CONFIGURATION DIALOG".
586 (Note that the XTerm window(s) persist while you advance to further
588 dialogs in virt-p2v, therefore it's unnecessary to jump back and
589 forth between virt-p2v dialogs just for entering additional shell
590 commands in the XTerm window(s).)
591 2. Using "vi" or another text editor, set the iSCSI initiator name in
593 /etc/iscsi/initiatorname.iscsi, for example:
594 InitiatorName=iqn.1994-05.com.redhat:846e82c634
596 If the file does not exist, create it. (Remember that this file is
598 part of the virt-p2v Live environment, therefore saving it does not
599 modify any hard disks.)
600 3. Configure any further iSCSI initiator details completely that are
602 required by the iSCSI target that you intend to log in to; that is,
603 before you issue the first "iscsiadm" command below. This includes
604 the CHAP user name and password if the target authenticates the
605 initiator with CHAP, and the reverse direction CHAP user name and
606 password too, if you want to ascertain the identity of the target
607 on the initiator as well (this is called "mutual authentication").
608 Completing the configuration at this stage is important because the
610 first "iscsiadm" command will start up the "iscsid" service, and
611 configuration changes with that service already running will not
612 (or may not) take effect until/unless you restart the service using
613 "systemctl".
614 4. Discover the iSCSI targets offered by the desired host:
616 iscsiadm -m discovery -t st -p IP_ADDRESS
618 The command should respond with a two-column list of targets. The
620 symbolic target names are in the right hand side column, for
621 example:
622 10.64.24.179:3260,1 iqn.2006-04.example:444
624 5. Picking an appropriate target from the right hand side column of
626 the previous step's output, log in to the target:
627 iscsiadm -m node -T TARGET -l
629 This command will inform you whether the login attempt was
631 successful.
632 6. In case the login succeeds, a scan for LUNs on the iSCSI target
634 will commence at once. There are two pitfalls here. One,
635 dependent on network characteristics, the scan may take several
636 (tens of) seconds. Two, even if the login succeeds, ACLs on the
637 target may silently prevent the initiator from seeing particular
638 LUNs -- meaning that no new /dev/sdX nodes will appear. This is
639 why it is important to get the initiator name (and, potentially,
640 CHAP authentication) correct at the very beginning of this
641 procedure.
642 Verify the results of the target scan with the "dmesg" command,
644 and/or with
645 ls -l /dev/disk/by-path/ip-*-iscsi-*-lun-*
647 If these symlinks exist, containing the "IP_ADDRESS" from step 4
649 and the "TARGET" name from step 5 in their filenames, then the
650 target scan has successfully found the corresponding LUNs.
651 7. Once the remote LUNs have been successfully enumerated, click the
653 "Refresh disks" button in the "DISK AND NETWORK CONFIGURATION
654 DIALOG".
655
657 Timeouts
658 As described below (see "HOW VIRT-P2V WORKS") virt-p2v makes several
659 long-lived ssh connections to the conversion server. If these
660 connections time out then virt-p2v will fail.
661 To test if a timeout might be causing problems, open an XTerm on the
663 virt-p2v machine, "ssh root@conversion-server", and leave it for at
664 least an hour. If the session disconnects without you doing anything,
665 then there is a timeout which you should turn off.
666 Timeouts happen because:
668 "TIMEOUT" or "TMOUT" environment variable
670 Check if one of these environment variables is set in the root
671 shell on the conversion server.
672 sshd "ClientAlive*" setting
674 Check for "ClientAlive*" settings in "/etc/ssh/sshd_config" on the
675 conversion server.
676 Firewall or NAT settings
678 Check if there is a firewall or NAT box between virt-p2v and the
679 conversion server, and if this firewall drops idle connections
680 after a too-short time.
681 virt-p2v ≥ 1.36 attempts to work around firewall timeouts by
683 sending ssh keepalive messages every 5 minutes.
684
686 --help
687 Display help.
688 --cmdline=CMDLINE
690 This is used for debugging. Instead of parsing the kernel command
691 line from /proc/cmdline, parse the string parameter "CMDLINE".
692 --colors
694 --colours
695 Use ANSI colour sequences to colourize messages. This is the
696 default when the output is a tty. If the output of the program is
697 redirected to a file, ANSI colour sequences are disabled unless you
698 use this option.
699 --iso
701 This flag is passed to virt-p2v when it is launched inside the
702 virt-p2v ISO environment, ie. when it is running on a real physical
703 machine (and thus not when testing). It enables various dangerous
704 features such as the Shutdown popup button.
705 --test-disk=/PATH/TO/DISK.IMG
707 For testing or debugging purposes, replace /dev/sda with a local
708 file. You must use an absolute path. Note that the "Refresh
709 disks" button will be disabled in the "DISK AND NETWORK
710 CONFIGURATION DIALOG" of the GUI.
711 -v
713 --verbose
714 In libguestfs ≥ 1.33.41, debugging is always enabled on the
715 conversion server, and this option does nothing.
716 -V
718 --version
719 Display version number and exit.
720
722 Note this section is not normative. We may change how virt-p2v works
723 at any time in the future.
724 As described above, virt-p2v runs on a physical machine, interrogates
726 the user or the kernel command line for configuration, and then
727 establishes one or more ssh connections to the virt-v2v conversion
728 server. The ssh connections are interactive shell sessions to the
729 remote host, but the commands sent are generated entirely by virt-p2v
730 itself, not by the user. For data transfer, virt-p2v will use the
731 reverse port forward feature of ssh (ie. "ssh -R").
732 It will first make one or more test connections, which are used to
734 query the remote version of virt-v2v and its features. The test
735 connections are closed before conversion begins.
736 ┌──────────────┐ ┌─────────────────┐
738 │ virt-p2v │ │ virt-v2v │
739 │ (physical │ control connection │ (conversion │
740 │ server) ╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍▶ server) │
741 └──────────────┘ └─────────────────┘
742 Once virt-p2v is ready to start conversion, it will open a single ssh
744 control connection. It first sends a mkdir command to create a
745 temporary directory on the conversion server. The directory name is
746 randomly chosen and is displayed in the GUI. It has the form:
747 /tmp/virt-p2v-YYYYMMDD-XXXXXXXX
749 where "YYYYMMDD" is the current date, and the ‘X’s are random
751 characters.
752 Into this directory are written various files which include:
754 dmesg
756 lscpu
757 lspci
758 lsscsi
759 lsusb
760 (before conversion)
761 The output of the corresponding commands (ie dmesg(1), lscpu(1)
763 etc) on the physical machine.
764 The dmesg output is useful for detecting problems such as missing
766 device drivers or firmware on the virt-p2v ISO. The others are
767 useful for debugging novel hardware configurations.
768 environment
770 (before conversion)
771 The content of the environment where virt-v2v(1) will run.
773 name
775 (before conversion)
776 The name (usually the hostname) of the physical machine.
778 physical.xml
780 (before conversion)
781 Libvirt XML describing the physical machine. It is used to pass
783 data about the physical source host to virt-v2v(1) via the -i
784 libvirtxml option.
785 Note this is not "real" libvirt XML (and must never be loaded into
787 libvirt, which would reject it anyhow). Also it is not the same as
788 the libvirt XML which virt-v2v generates in certain output modes.
789 p2v-version
791 v2v-version
792 (before conversion)
793 The versions of virt-p2v and virt-v2v respectively.
795 status
797 (after conversion)
798 The final status of the conversion. 0 if the conversion was
800 successful. Non-zero if the conversion failed.
801 time
803 (before conversion)
804 The start date/time of conversion.
806 virt-v2v-conversion-log.txt
808 (during/after conversion)
809 The conversion log. This is just the output of the virt-v2v
811 command on the conversion server. If conversion fails, you should
812 examine this log file, and you may be asked to supply the complete,
813 unedited log file in any bug reports or support tickets.
814 virt-v2v-wrapper.sh
816 (before conversion)
817 This is the wrapper script which is used when running virt-v2v.
819 For interest only, do not attempt to run this script yourself.
820 Before conversion actually begins, virt-p2v then makes one or more
822 further ssh connections to the server for data transfer.
823 The transfer protocol used currently is NBD (Network Block Device),
825 which is proxied over ssh. The NBD server is nbdkit(1), with
826 nbdkit-file-plugin(1) and socket activation.
827 There is one ssh connection per physical hard disk on the source
829 machine (the common case — a single hard disk — is shown below):
830 ┌──────────────┐ ┌─────────────────┐
832 │ virt-p2v │ │ virt-v2v │
833 │ (physical │ control connection │ (conversion │
834 │ server) ╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍▶ server) │
835 │ │ │ │
836 │ │ data connection │ │
837 │ ╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍▶ │
838 │ nbdkit ← ─┘ │ │└─ ← NBD │
839 │ /dev/sda │ │ requests │
840 ∼ ∼ ∼ ∼
841 └──────────────┘ └─────────────────┘
842 Although the ssh data connection is originated from the physical server
844 and terminates on the conversion server, in fact NBD requests flow in
845 the opposite direction. This is because the reverse port forward
846 feature of ssh ("ssh -R") is used to open a port on the loopback
847 interface of the conversion server which is proxied back by ssh to
848 nbdkit running on the physical machine. The effect is that virt-v2v
849 via libguestfs can open nbd connections which directly read the hard
850 disk(s) of the physical server.
851 Two layers of protection are used to ensure that there are no writes to
853 the hard disks: Firstly, the nbdkit -r (readonly) option is used.
854 Secondly libguestfs creates an overlay on top of the NBD connection
855 which stores writes in a temporary file on the conversion file.
856 The long "virt-v2v -i libvirtxml physical.xml ..." command is wrapped
858 inside a wrapper script and uploaded to the conversion server. The
859 final step is to run this wrapper script, in turn running the virt-v2v
860 command. The virt-v2v command references the physical.xml file (see
861 above), which in turn references the NBD listening port(s) of the data
862 connection(s).
863 Output from the virt-v2v command (messages, debugging etc) is saved in
865 the log file on the conversion server. Only informational messages are
866 sent back over the control connection to be displayed in the graphical
867 UI.
868
870 virt-p2v-make-disk(1), virt-p2v-make-kickstart(1),
871 virt-p2v-make-kiwi(1), virt-v2v(1), nbdkit(1), nbdkit-file-plugin(1),
872 ssh(1), sshd(8), sshd_config(5), http://libguestfs.org/.
873
875 Matthew Booth
876 John Eckersberg
878 Richard W.M. Jones http://people.redhat.com/~rjones/
880 Mike Latimer
882 Pino Toscano
884 Tingting Zheng
886
888 Copyright (C) 2009-2019 Red Hat Inc.
889
891 This program is free software; you can redistribute it and/or modify it
892 under the terms of the GNU General Public License as published by the
893 Free Software Foundation; either version 2 of the License, or (at your
894 option) any later version.
895 This program is distributed in the hope that it will be useful, but
897 WITHOUT ANY WARRANTY; without even the implied warranty of
898 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
899 General Public License for more details.
900 You should have received a copy of the GNU General Public License along
902 with this program. If not, see <https://www.gnu.org/licenses/>.
903
905 To get a list of bugs against libguestfs (which include virt-p2v), use
906 this link:
907 https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
908 To report a new bug against libguestfs, use this link:
910 https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
911 When reporting a bug, please supply:
913 • The version of virt-p2v.
915 • Where you got virt-p2v (eg. which Linux distro, compiled from
917 source, etc)
918 • Describe the bug accurately and give a way to reproduce it.
920virt-p2v-1.42.3 2023-07-22 virt-p2v(1)