Voozh

SYNOPSIS

virt-v2v -ic vpx://vcenter.example.com/Datacenter/esxi vmware_guest
virt-v2v -ic vpx://vcenter.example.com/Datacenter/esxi vmware_guest \
-o rhev -os rhev.nfs:/export_domain --network rhevm
virt-v2v -i libvirtxml guest-domain.xml -o local -os /var/tmp
virt-v2v -i disk disk.img -o local -os /var/tmp
virt-v2v -i disk disk.img -o glance
virt-v2v -ic qemu:///system qemu_guest --in-place

DESCRIPTION

Virt-v2v converts guests from a foreign hypervisor to run on It can read Linux and Windows guests running on VMware, Xen, Hyper-V and some other hypervisors, and convert them to managed by libvirt, OpenStack, oVirt, Red Hat Enterprise Virtualisation () or several other targets.

There is also a companion front-end called virt-p2v(1) which comes as an or image that can be booted on physical machines to virtualize those machines (physical to virtual, or p2v).

This manual page documents the rewritten virt-v2v included in libguestfs ≥ 1.28.

INPUT AND OUTPUT MODES

 ┌────────────┐ ┌─────────▶ -o null
 -i disk ────────────┐ │ │ ─┘┌───────▶ -o local
 -i ova ──────────┐ └──▶ │ virt-v2v │ ──┘┌───────▶ -o qemu
 └────▶ │ conversion │ ───┘┌────────────┐
 VMware─▶┌────────────┐ │ server │ ────▶ -o libvirt │─▶ KVM
 Xen ───▶│ -i libvirt ──▶ │ │ │ (default) │
 ... ───▶│ (default) │ │ │ ──┐ └────────────┘
 └────────────┘ │ │ ─┐└──────▶ -o glance
 -i libvirtxml ─────────▶ │ │ ┐└─────────▶ -o rhev
 └────────────┘ └──────────▶ -o vdsm

Virt-v2v has a number of possible input and output modes, selected using the -i and -o options. Only one input and output mode can be selected for each run of virt-v2v.

-i disk is used for reading from local disk images (mainly for testing).

-i libvirt is used for reading from any libvirt source. Since libvirt can connect to many different hypervisors, it is used for reading guests from VMware, Xen and more. The -ic option selects the precise libvirt source.

-i libvirtxml is used to read from libvirt files. This is the method used by virt-p2v(1) behind the scenes.

-i ova is used for reading from a VMware ova source file.

-o glance is used for writing to OpenStack Glance.

-o libvirt is used for writing to any libvirt target. Libvirt can connect to local or remote hypervisors. The -oc option selects the precise libvirt target.

-o local is used to write to a local disk image with a local libvirt configuration file (mainly for testing).

-o qemu writes to a local disk image with a shell script for booting the guest directly in qemu (mainly for testing).

-o rhev is used to write to a RHEV-M / oVirt target. -o vdsm is only used when virt-v2v runs under control.

--in-place instructs virt-v2v to customize the guest in the input virtual machine, instead of creating a new in the target hypervisor.

EXAMPLES

Convert from VMware vCenter server to local libvirt

You have a VMware vCenter server called , a datacenter called , and an ESXi hypervisor called . You want to convert a guest called to run locally under libvirt.

 virt-v2v -ic vpx://vcenter.example.com/Datacenter/esxi vmware_guest

In this case you will most likely have to run virt-v2v as , since it needs to talk to the system libvirt daemon and copy the guest disks to /var/lib/libvirt/images.

For more information see `` below.

Convert from VMware to RHEV-M/oVirt

This is the same as the previous example, except you want to send the guest to a RHEV-M Export Storage Domain which is located remotely (over ) at . If you are unclear about the location of the Export Storage Domain you should check the settings on your RHEV-M management console. Guest network interface(s) are connected to the target network called .

 virt-v2v -ic vpx://vcenter.example.com/Datacenter/esxi vmware_guest \
 -o rhev -os rhev.nfs:/export_domain --network rhevm

In this case the host running virt-v2v acts as a conversion server.

Note that after conversion, the guest will appear in the RHEV-M Export Storage Domain, from where you will need to import it using the RHEV-M user interface. (See ``).

Convert disk image to OpenStack glance

Given a disk image from another hypervisor that you want to convert to run on OpenStack (only KVM-based OpenStack is supported), you can do:

 virt-v2v -i disk disk.img -o glance

See `` below.

Convert disk image to disk image

Given a disk image from another hypervisor that you want to convert to run on you have two options. The simplest way is to try:

 virt-v2v -i disk disk.img -o local -os /var/tmp

where virt-v2v guesses everything about the input disk.img and (in this case) writes the converted result to /var/tmp.

A more complex method is to write some libvirt describing the input guest (if you can get the source hypervisor to provide you with libvirt then so much the better). You can then do:

 virt-v2v -i libvirtxml guest-domain.xml -o local -os /var/tmp

Since guest-domain.xml contains the path(s) to the guest disk image(s) you do not need to specify the name of the disk image on the command line.

To convert a local disk image and immediately boot it in local qemu, do:

 virt-v2v -i disk disk.img -o qemu -os /var/tmp --qemu-boot

SUPPORT MATRIX

Hypervisors (Input)

VMware ESXi: Must be managed by VMware vCenter ≥ 5.0. Unmanaged, direct input from ESXi is not supported.
exported from VMware: OVAs from other hypervisors will not work.
Xen
Citrix Xen: Citrix Xen has not been recently tested.
Hyper-V: Not recently tested. Requires that you export the disk or use virt-p2v(1) on Hyper-V.
Direct from disk images: Only disk images exported from supported hypervisors, and using container formats supported by qemu.
Physical machines: Using the virt-p2v(1) tool.

Hypervisors (Output)

and only.

Virtualization management systems (Output)

OpenStack Glance
Red Hat Enterprise Virtualization () 2.2 and up
Local libvirt: And hence virsh(1), virt-manager(1), and similar tools.
Local disk

Guests

Red Hat Enterprise Linux 3, 4, 5, 6, 7

CentOS 3, 4, 5, 6, 7

Scientific Linux 3, 4, 5, 6, 7

Oracle Linux

Fedora

and up

OpenSUSE 10 and up

Windows to Windows 8.1 / Windows Server 2012 R2

We use Windows internal version numbers, see https://en.wikipedia.org/wiki/List_of_Microsoft_Windows_versions

Currently to are supported.

See `` below for additional notes on converting Windows guests.

Guest firmware

or for all guest types (but see `` below).

OPTIONS

--help

Display help.

-b ...

--bridge ...

See --network below.

--compressed

Write a compressed output file. This is only allowed if the output format is qcow2 (see -of below), and is equivalent to the -c option of qemu-img(1).

--dcpath Folder/Datacenter

You don't need to use this parameter if you have libvirt ≥ 1.2.20.

For VMware vCenter, override the parameter used to select the datacenter. Virt-v2v can usually calculate this from the but if it gets it wrong, then you can override it using this setting. Go to your vCenter web folder interface, eg. (without a trailing slash), and examine the parameter in the URLs that appear on this page.

--debug-gc

Debug garbage collection and memory allocation. This is only useful when debugging memory problems in virt-v2v or the OCaml libguestfs bindings.

--debug-overlays

Save the overlay file(s) created during conversion. This option is only used for debugging virt-v2v and may be removed in a future version.

-i disk

Set the input method to disk.

In this mode you can read a virtual machine disk image with no metadata. virt-v2v tries to guess the best default metadata. This is usually adequate but you can get finer control (eg. of memory and vCPUs) by using -i libvirtxml instead. Only guests that use a single disk can be imported this way.

-i libvirt

Set the input method to libvirt. This is the default.

In this mode you have to specify a libvirt guest name or on the command line. You may also specify a libvirt connection (see -ic).

-i libvirtxml

Set the input method to libvirtxml.

In this mode you have to pass a libvirt file on the command line. This file is read in order to get metadata about the source guest (such as its name, amount of memory), and also to locate the input disks. See `` -i libvirtxml below.

-i local

This is the same as -i disk.

-i ova

Set the input method to ova.

In this mode you can read a VMware ova file. Virt-v2v will read the ova manifest file and check the vmdk volumes for validity (checksums) as well as analyzing the ovf file, and then convert the guest. See `` below

-ic libvirtURI

Specify a libvirt connection to use when reading the guest. This is only used when -i libvirt.

Only local libvirt connections, VMware vCenter connections, or Xen remote connections can be used. Other remote libvirt connections will not work in general.

XEN PARAVIRTUALIZED GUESTS

Older versions of virt-v2v could turn a Xen paravirtualized () guest into a guest by installing a new kernel. This version of virt-v2v does not attempt to install any new kernels. Instead it will give you an error if there are only Xen kernels available.

Therefore before conversion you should check that a regular kernel is installed. For some older Linux distributions, this means installing a kernel from the table below:

 RHEL 3 (Does not apply, as there was no Xen PV kernel)
 
 RHEL 4 i686 with > 10GB of RAM: install 'kernel-hugemem'
 i686 SMP: install 'kernel-smp'
 other i686: install 'kernel'
 x86-64 SMP with > 8 CPUs: install 'kernel-largesmp'
 x86-64 SMP: install 'kernel-smp'
 other x86-64: install 'kernel'
 
 RHEL 5 i686: install 'kernel-PAE'
 x86-64: install 'kernel'
 
 SLES 10 i586 with > 10GB of RAM: install 'kernel-bigsmp'
 i586 SMP: install 'kernel-smp'
 other i586: install 'kernel-default'
 x86-64 SMP: install 'kernel-smp'
 other x86-64: install 'kernel-default'
 
 SLES 11+ i586: install 'kernel-pae'
 x86-64: install 'kernel-default'
 Windows (Does not apply, as there is no Xen PV Windows kernel)

ENABLING VIRTIO

``Virtio'' is the name for a set of drivers which make disk (block device), network and other guest operations work much faster on

Older versions of virt-v2v could install these drivers for certain Linux guests. This version of virt-v2v does not attempt to install new Linux kernels or drivers, but will warn you if they are not installed already.

In order to enable virtio, and hence improve performance of the guest after conversion, you should ensure that the minimum versions of packages are installed before conversion, by consulting the table below.

 RHEL 3 No virtio drivers are available
 
 RHEL 4 kernel >= 2.5.9-89.EL
 lvm2 >= 2.02.42-5.el4
 device-mapper >= 1.02.28-2.el4
 selinux-policy-targeted >= 1.17.30-2.152.el4
 policycoreutils >= 1.18.1-4.13
 
 RHEL 5 kernel >= 2.6.18-128.el5
 lvm2 >= 2.02.40-6.el5
 selinux-policy-targeted >= 2.4.6-203.el5
 
 RHEL 6+ All versions support virtio
 
 Fedora All versions support virtio
 
 SLES 11+ All versions support virtio
 
 SLES 10 kernel >= 2.6.16.60-0.85.1
 
 OpenSUSE 11+ All versions support virtio
 
 OpenSUSE 10 kernel >= 2.6.25.5-1.1
 Windows Drivers are installed from the directory pointed to by
 "VIRTIO_WIN" environment variable
 (/usr/share/virtio-win by default) if present

RHEL 4

SELinux relabel appears to hang forever

In ≤ 4.7 there was a bug which causes SELinux relabelling to appear to hang forever at:

 *** Warning -- SELinux relabel is required. ***
 *** Disabling security enforcement. ***
 *** Relabeling could take a very long time, ***
 *** depending on file system size. ***

In reality it is waiting for you to press a key (but there is no visual indication of this). You can either hit the key, at which point the guest will finish relabelling and reboot, or you can install policycoreutils ≥ 1.18.1-4.13 before starting the v2v conversion. See also https://bugzilla.redhat.com/show_bug.cgi?id=244636

WINDOWS

Windows ≥ 8 Fast Startup is incompatible with virt-v2v

Guests which use the Windows ≥ 8 ``Fast Startup'' feature (or guests which are hibernated) cannot be converted with virt-v2v. You will see an error:

 virt-v2v: error: unable to mount the disk image for writing. This has
 probably happened because Windows Hibernation or Fast Restart is being
 used in this guest. You have to disable this (in the guest) in order
 to use virt-v2v.

As the message says, you need to boot the guest and disable the ``Fast Startup'' feature (Control Panel → Power Options → Choose what the power buttons do → Change settings that are currently unavailable → Turn on fast startup), and shut down the guest, and then you will be able to convert it.

For more information, see: `` in guestfs(3).

Boot failure: 0x0000007B

This boot failure is caused by Windows being unable to find or load the right disk driver (eg. viostor.sys). If you experience this error, here are some things to check:

First ensure that the guest boots on the source hypervisor before conversion.
Check you have the Windows virtio drivers available in /usr/share/virtio-win, and that virt-v2v did not print any warning about not being able to install virtio drivers.
On Red Hat Enterprise Linux 7, you will need to install the signed drivers available in the package. If you do not have access to the signed drivers, then you will probably need to disable driver signing in the boot menus.
Check that you are presenting a virtio-blk interface (not virtio-scsi and not ide) to the guest. On the qemu/KVM command line you should see something similar to this:
```
 ... -drive file=windows-sda,if=virtio ...
```
In libvirt you should see:
```
 <target dev='vda' bus='virtio'/>
```
Check that Windows Group Policy does not prevent the driver from being installed or used. Try deleting Windows Group Policy before conversion.
Check there is no anti-virus or other software which implements Group Policy-like prohibitions on installing or using new drivers.
Enable boot debugging and check the viostor.sys driver is being loaded.

OpenStack and Windows reactivation

OpenStack does not offer stable device / addresses to guests. Every time it creates or starts a guest, it regenerates the libvirt for that guest from scratch. The libvirt will have no <address> fields. Libvirt will then assign addresses to devices, in a predictable manner. Addresses may change if any of the following are true:

A new disk or network device has been added or removed from the guest.
The version of OpenStack or (possibly) libvirt has changed.

Because Windows does not like ``hardware'' changes of this kind, it may trigger Windows reactivation.

This can also prevent booting with a 7B error [see previous section] if the guest has group policy containing .

UEFI

VMware allows you to present firmware to guests (instead of the ordinary ). Virt-v2v can convert these guests, but requires that is supported by the target hypervisor.

Currently supports a partially open source firmware, and can run these guests.

Since support was only recently added to (in 2014/2015), not all target environments support guests yet:

on libvirt, qemu: Supported. Virt-v2v will generate the correct libvirt (metadata) automatically, but note that the same version of must be installed on the conversion host as is installed on the target hypervisor, else you will have to adjust paths in the metadata.
on OpenStack: Not supported.
on: Not supported.

NETWORKS AND BRIDGES

Guests are usually connected to one or more networks, and when converted to the target hypervisor you usually want to reconnect those networks at the destination. The options --network and --bridge allow you to do that.

If you are unsure of what networks and bridges are in use on the source hypervisor, then you can examine the source metadata (libvirt vCenter information, etc.). Or you can run virt-v2v with the --print-source option which causes virt-v2v to print out the information it has about the guest on the source and then exit.

In the --print-source output you will see a section showing the guest's Network Interface Cards (NICs):

 $ virt-v2v [-i ...] --print-source name
 [...]
 NICs:
 Network "default" mac: 52:54:00:d0:cf:0e

This is typical of a libvirt guest: It has a single network interface connected to a network called .

To map a specific network to a target network, for example on the source to on the target, use:

 virt-v2v [...] --network default:rhevm

To map every network to a target network, use:

 virt-v2v [...] --network rhevm

Bridges are handled in the same way, but you have to use the --bridge option instead. For example:

 $ virt-v2v [-i ...] --print-source name
 [...]
 NICs:
 Bridge "br0"
 
 $ virt-v2v [...] --bridge br0:targetbr

INPUT FROM VMWARE VCENTER SERVER

Virt-v2v is able to import guests from VMware vCenter Server.

vCenter ≥ 5.0 is required. If you don't have vCenter, using is recommended instead (see `` below), or if that is not possible then see `` ESXi .

Virt-v2v uses libvirt for access to vCenter, and therefore the input mode should be -i libvirt. As this is the default, you don't need to specify it on the command line.

For Windows guests, you should remove VMware tools before conversion. Although this is not strictly necessary, and the guest will still be able to run, if you don't do this then the converted guest will complain on every boot. The tools cannot be removed after conversion because the uninstaller checks if it is running on VMware and refuses to start (which is also the reason that virt-v2v cannot remove them).

This is not necessary for Linux guests, as virt-v2v is able to remove VMware tools.

The libvirt of a vCenter server looks something like this:

 vpx://user@server/Datacenter/esxi

where:

"user@": is the (optional, but recommended) user to connect as.
If the username contains a backslash (eg. ) then you will need to URI-escape that character using : (5c is the hexadecimal code for backslash.) Other punctuation may also have to be escaped.
"server": is the vCenter Server (not hypervisor).
"Datacenter": is the name of the datacenter.
If the name contains a space, replace it with the URI-escape code .
"esxi": is the name of the ESXi hypervisor running the guest.

If the VMware deployment is using folders, then these may need to be added to the eg:

 vpx://user@server/Folder/Datacenter/esxi

For full details of libvirt URIs, see: http://libvirt.org/drvesx.html

Typical errors from libvirt / virsh when the is wrong include:

Could not find datacenter specified in [...]
Could not find compute resource specified in [...]
Path [...] does not specify a compute resource
Path [...] does not specify a host system
Could not find host system specified in [...]

Use the virsh(1) command to list the guests on the vCenter Server like this:

 $ virsh -c 'vpx://[email protected]/Datacenter/esxi' list --all
 Enter root's password for vcenter.example.com: ***
 
 Id Name State
 ----------------------------------------------------
 - Fedora 20 shut off
 - Windows 2003 shut off

If you get an error ``Peer certificate cannot be authenticated with given certificates'' or similar, then you can either import the vCenter host's certificate, or bypass signature verification by adding the flag:

 $ virsh -c 'vpx://[email protected]/Datacenter/esxi?no_verify=1' list --all

You should also try dumping the metadata from any guest on your server, like this:

 $ virsh -c 'vpx://[email protected]/Datacenter/esxi' dumpxml "Windows 2003"
 <domain type='vmware'>
 <name>Windows 2003</name>
 [...]
 </domain>

If the above commands do not work, then virt-v2v is not going to work either. Fix your libvirt configuration and/or your VMware vCenter Server before continuing.

To import a particular guest from vCenter Server, do:

 $ virt-v2v -ic 'vpx://[email protected]/Datacenter/esxi?no_verify=1' \
 "Windows 2003" \
 -o local -os /var/tmp

where is the name of the guest (which must be shut down).

Note that you may be asked for the vCenter password twice. This happens once because libvirt needs it, and a second time because virt-v2v itself connects directly to the server. Use --password-file to supply a password via a file.

In this case the output flags are set to write the converted guest to a temporary directory as this is just an example, but you can also write to libvirt or any other supported target.

NON-ADMINISTRATOR

Instead of using the vCenter Administrator role, you can create a custom non-administrator role to perform the conversion. You will however need to give it a minimum set of permissions as follows:

1.

Create a custom role in vCenter.

2.

Enable (check) the following objects:

 Datastore:
 - Browse datastore
 - Low level file operations
 
 Sessions:
 - Validate session
 
 Virtual Machine:
 Provisioning:
 - Allow disk access
 - Allow read-only disk access
 - Guest Operating system management by VIX API

INPUT FROM VMWARE OVA

Virt-v2v is able to import guests from VMware's (Open Virtualization Appliance) files. Only OVAs exported from VMware vSphere will work.

This is not necessary for Linux guests, as virt-v2v is able to remove VMware tools.

To create an in vSphere, use the ``Export Template'' option (from the context menu, or from the File menu). Either ``Folder of files'' () or ``Single file'' () will work, but is probably easier to deal with. files are really just uncompressed tar files, so you can use commands like to view their contents.

Create with ovftool

You can also use VMware's proprietary :

 ovftool --noSSLVerify \
 vi://USER:[email protected]/VM \
 VM.ova

To connect to vCenter:

 ovftool --noSSLVerify \
 vi://USER:[email protected]/DATACENTER-NAME/vm/VM \
 VM.ova

For Active Directory-aware authentication, you have to express the character in the form of its ascii hex-code ():

 vi://DOMAIN%5cUSER:PASSWORD@...

To import an file called .ova, do;

 $ virt-v2v -i ova VM.ova -o local -os /var/tmp

If you exported the guest as a ``Folder of files'', or if you unpacked the tarball yourself, then you can point virt-v2v at the directory containing the files:

 $ virt-v2v -i ova /path/to/files -o local -os /var/tmp

INPUT FROM VMWARE ESXi HYPERVISOR

Virt-v2v cannot access an ESXi hypervisor directly. You should use the method above (see ``) if possible, as it is much faster and requires much less disk space than the method described in this section.

You can use the virt-v2v-copy-to-local(1) tool to copy the guest off the hypervisor into a local file, and then convert it.

ESXi:

This is not necessary for Linux guests, as virt-v2v is able to remove VMware tools.

ESXi:

The libvirt for VMware ESXi hypervisors will look something like this:

 esx://[email protected]?no_verify=1

The parameter disables certificate checking.

ESXi: ESXi

Use the virsh(1) command to test the and list the remote guests available:

 $ virsh -c esx://[email protected]?no_verify=1 list --all
 Enter root's password for esxi.example.com: ***
 Id Name State
 ----------------------------------------------------
 - guest shut off

ESXi:

Using the libvirt as the -ic option, copy one of the guests to the local machine:

 $ virt-v2v-copy-to-local -ic esx://[email protected]?no_verify=1 guest

This creates guest.xml, guest-disk1, ...

ESXi:

Perform the conversion of the guest using virt-v2v:

 $ virt-v2v -i libvirtxml guest.xml -o local -os /var/tmp

ESXi:

Remove the guest.xml and guest-disk* files.

INPUT FROM RHEL 5 XEN

Virt-v2v is able to import Xen guests from Xen hosts.

Virt-v2v uses libvirt for access to the remote Xen host, and therefore the input mode should be -i libvirt. As this is the default, you don't need to specify it on the command line.

SSH-AGENT

Currently you must enable passwordless access to the remote Xen host from the virt-v2v conversion server.

You must also use ssh-agent, and add your ssh public key to /root/.ssh/authorized_keys (on the Xen host).

After doing this, you should check that passwordless access works from the virt-v2v server to the Xen host. For example:

 $ ssh [email protected]
 [ logs straight into the shell, no password is requested ]

Note that password-interactive and Kerberos access are not supported. You have to set up ssh access using ssh-agent and authorized_keys.

Use the virsh(1) command to list the guests on the remote Xen host:

 $ virsh -c xen+ssh://[email protected] list --all
 Id Name State
 ----------------------------------------------------
 0 Domain-0 running
 - rhel49-x86_64-pv shut off

You should also try dumping the metadata from any guest on your server, like this:

 $ virsh -c xen+ssh://[email protected] dumpxml rhel49-x86_64-pv
 <domain type='xen'>
 <name>rhel49-x86_64-pv</name>
 [...]
 </domain>

If the above commands do not work, then virt-v2v is not going to work either. Fix your libvirt configuration or the remote server before continuing.

If the guest disks are located on a host block device, then the conversion will fail. See `` below for a workaround.

To import a particular guest from a Xen server, do:

 $ virt-v2v -ic 'xen+ssh://[email protected]' \
 rhel49-x86_64-pv \
 -o local -os /var/tmp

where is the name of the guest (which must be shut down).

In this case the output flags are set to write the converted guest to a temporary directory as this is just an example, but you can also write to libvirt or any other supported target.

Currently virt-v2v cannot directly access a Xen guest (or any guest located remotely over ssh) if that guest's disks are located on host block devices.

To tell if a Xen guest uses host block devices, look at the guest You will see:

 <disk type='block' device='disk'>
 ...
 <source dev='/dev/VG/guest'/>

where , and are all indications that the disk is located on a host block device.

This happens because the qemu ssh block driver that we use to access remote disks uses the ssh sftp protocol, and this protocol cannot correctly detect the size of host block devices.

The workaround is to copy the guest over to the conversion server, using the separate virt-v2v-copy-to-local(1) tool, followed by running virt-v2v. You will need sufficient space on the conversion server to store a full copy of the guest.

 virt-v2v-copy-to-local -ic xen+ssh://[email protected] guest
 virt-v2v -i libvirtxml guest.xml -o local -os /var/tmp
 rm guest.xml guest-disk*

OUTPUT TO LIBVIRT

The -o libvirt option lets you upload the converted guest to a libvirt-managed host. There are several limitations:

You can only use a local libvirt connection [see below for how to workaround this].
The -os pool option must specify a directory pool, not anything more exotic such as iSCSI [but see below].
You can only upload to a hypervisor.

To output to a remote libvirt instance and/or a non-directory storage pool you have to use the following workaround:

1.

Use virt-v2v in -o local mode to convert the guest disks and metadata into a local temporary directory:

 virt-v2v [...] -o local -os /var/tmp

This creates two (or more) files in /var/tmp called:

 /var/tmp/NAME.xml # the libvirt XML (metadata)
 /var/tmp/NAME-sda # the guest's first disk

(for substitute the guest's name).

2.

Upload the converted disk(s) into the storage pool called :

 size=$(stat -c%s /var/tmp/NAME-sda)
 virsh vol-create-as POOL NAME-sda $size --format raw
 virsh vol-upload --pool POOL NAME-sda /var/tmp/NAME-sda

3.

Edit /var/tmp/NAME.xml to change /var/tmp/NAME-sda to the pool name. In other words, locate the following bit of

 <disk type='file' device='disk'>
 <driver name='qemu' type='raw' cache='none' />
 <source file='/var/tmp/NAME-sda' />
 <target dev='hda' bus='ide' />
 </disk>

and change two things: The attribute must be changed to , and the element must be changed to include and attributes:

 <disk type='volume' device='disk'>
 ...
 <source pool='POOL' volume='NAME-sda' />
 ...
 </disk>

4.

Define the final guest in libvirt:

 virsh define /var/tmp/NAME.xml

OUTPUT TO RHEV

This section only applies to the -o rhev output mode. If you use virt-v2v from the RHEV-M user interface, then behind the scenes the import is managed by using the -o vdsm output mode (which end users should not try to use directly).

You have to specify -o rhev and an -os option that points to the RHEV-M Export Storage Domain. You can either specify the server and mountpoint, eg. , or you can mount that first and point to the directory where it is mounted, eg. . Be careful not to point to the Data Storage Domain by accident as that will not work.

On successful completion virt-v2v will have written the new guest to the Export Storage Domain, but it will not yet be ready to run. It must be imported into using the before it can be used.

In ≥ 2.2 this is done from the Storage tab. Select the export domain the guest was written to. A pane will appear underneath the storage domain list displaying several tabs, one of which is `` Import''. The converted guest will be listed here. Select the appropriate guest an click ``Import''. See the documentation for additional details.

If you export several guests, then you can import them all at the same time through the

OUTPUT TO GLANCE

To output to OpenStack Glance, use the -o glance option.

This runs the glance(1) program which must be installed on the virt-v2v conversion host. For authentication to work, you will need to set environment variables. In most cases you can do this by sourcing a file called something like keystonerc_admin.

Virt-v2v adds metadata for the guest to Glance, describing such things as the guest operating system and what drivers it requires. The command will display the metadata as ``Property'' fields such as and .

Glance and sparseness

Glance image upload doesn't appear to correctly handle sparseness. For this reason, using qcow2 will be faster and use less space on the Glance server. Use the virt-v2v -of qcow2 option.

Glance and multiple disks

If the guest has a single disk, then the name of the disk in Glance will be the name of the guest. You can control this using the -on option.

Glance doesn't have a concept of associating multiple disks with a single guest, and Nova doesn't allow you to boot a guest from multiple Glance disks either. If the guest has multiple disks, then the first (assumed to be the system disk) will have the name of the guest, and the second and subsequent data disks will be called guestname, guestname etc. It may be best to leave the system disk in Glance, and import the data disks to Cinder (see next section).

Importing disks into Cinder

Since most virt-v2v guests are ``pets'', Glance is perhaps not the best place to store them. There is no way for virt-v2v to upload directly to Cinder (https://bugzilla.redhat.com/1155229). There are two ways to upload to Cinder:

1.

Import the image to Glance first (ie. -o glance) and then copy it to Cinder:

 cinder create --image-id <GLANCE-IMAGE-UUID> <SIZE>

2.

Create (through some other means) a new volume / in your Cinder backing store. Migrate the guest to this volume (using -o local). Then ask Cinder to take over management of the volume using:

 cinder manage <VOLUMEREF>

RESOURCE REQUIREMENTS

Network

The most important resource for virt-v2v appears to be network bandwidth. Virt-v2v should be able to copy guest data at gigabit ethernet speeds or greater.

Ensure that the network connections between servers (conversion server, server, vCenter, Xen) are as fast and as low latency as possible.

Disk space

Virt-v2v places potentially large temporary files in (which is /var/tmp if you don't set it). Using tmpfs is a bad idea.

For each guest disk, an overlay is stored temporarily. This stores the changes made during conversion, and is used as a cache. The overlays are not particularly large - tens or low hundreds of megabytes per disk is typical. In addition to the overlay(s), input and output methods may use disk space, as outlined in the table below.

-i ova: This temporarily places a full copy of the uncompressed source disks in .
-o glance: This temporarily places a full copy of the output disks in .
-o local
-o qemu: You must ensure there is sufficient space in the output directory for the converted guest.
-o null: This temporarily places a full copy of the output disks in .

VMware vCenter resources

Copying from VMware vCenter is currently quite slow, but we believe this to be an issue with VMware. Ensuring the VMware ESXi hypervisor and vCenter are running on fast hardware with plenty of memory should alleviate this.

Compute power and

Virt-v2v is not especially compute or intensive. If you are running many parallel conversions, then you may consider allocating one core and between 512 and 1 of per running instance.

Virt-v2v can be run in a virtual machine.

POST-CONVERSION TASKS

Guest network configuration

Virt-v2v cannot currently reconfigure a guest's network configuration. If the converted guest is not connected to the same subnet as the source, its network configuration may have to be updated. See also virt-customize(1).

Converting a Windows guest

When converting a Windows guests, the conversion process is split into two stages:

1.: Offline conversion.
2.: First boot.

The guest will be bootable after the offline conversion stage, but will not yet have all necessary drivers installed to work correctly. These will be installed automatically the first time the guest boots.

N.B. Take care not to interrupt the automatic driver installation process when logging in to the guest for the first time, as this may prevent the guest from subsequently booting correctly.

FREE SPACE FOR CONVERSION

Virt-v2v checks there is sufficient free space in the guest filesystem to perform the conversion. Currently it checks:

Linux root filesystem or Windows "C:" drive: Minimum free space: 20
Linux /boot: Minimum free space: 50
This is because we need to build a new initramfs for some Enterprise Linux conversions.
Any other mountable filesystem: Minimum free space: 10

RUNNING VIRT-V2V AS ROOT OR NON-ROOT

Nothing in virt-v2v inherently needs root access, and it will run just fine as a non-root user. However, certain external features may require either root or a special user:

Mounting the Export Storage Domain: When using -o rhev -os server:/esd virt-v2v has to have sufficient privileges to mount the Export Storage Domain from .
You can avoid needing root here by mounting it yourself before running virt-v2v, and passing -os /mountpoint instead, but first of all read the next section ...
Writing to the Export Storage Domain as 36:36: RHEV-M cannot read files and directories from the Export Storage Domain unless they have You will see import problems if the is not correct.
When you run virt-v2v -o rhev as root, virt-v2v attempts to create files and directories with the correct ownership. If you run virt-v2v as non-root, it will probably still work, but you will need to manually change ownership after virt-v2v has finished.
Writing to libvirt: When using -o libvirt, you may need to run virt-v2v as root so that it can write to the libvirt system instance (ie. ) and to the default location for disk images (usually /var/lib/libvirt/images).
You can avoid this by setting up libvirt connection authentication, see http://libvirt.org/auth.html. Alternatively, use -oc qemu:///session, which will write to your per-user libvirt instance.
Writing to Glance: This does not need root (in fact it probably won't work), but may require either a special user and/or for you to source a script that sets authentication environment variables. Consult the Glance documentation.

DEBUGGING RHEV-M IMPORT FAILURES

When you export to the RHEV-M Export Storage Domain, and then import that guest through the RHEV-M you may encounter an import failure. Diagnosing these failures is infuriatingly difficult as the generally hides the true reason for the failure.

There are two log files of interest. The first is stored on the RHEV-M server itself, and is called /var/log/ovirt-engine/engine.log

The second file, which is the most useful, is found on the host ( stands for ``Storage Pool Manager''). This is a node that is elected to do all metadata modifications in the data center, such as image or snapshot creation. You can find out which host is the current from the ``Hosts'' tab ``Spm Status'' column. Once you have located the log into it and grab the file /var/log/vdsm/vdsm.log which will contain detailed error messages from low-level commands.

MINIMAL XML FOR -i libvirtxml OPTION

When using the -i libvirtxml option, you have to supply some libvirt Writing this from scratch is hard, so the template below is helpful.

Note this should only be used for testing and/or where you know what you're doing! If you have libvirt metadata for the guest, always use that instead.

 <domain type='kvm'>
 <name>NAME</name>
 <memory>1048576</memory>
 <vcpu>2</vcpu>
 <os>
 <type>hvm</type>
 <boot dev='hd'/>
 </os>
 <features>
 <acpi/>
 <apic/>
 <pae/>
 </features>
 <devices>
 <disk type='file' device='disk'>
 <driver name='qemu' type='raw'/>
 <source file='/path/to/disk/image'/>
 <target dev='hda' bus='ide'/>
 </disk>
 <interface type='network'>
 <mac address='52:54:00:01:02:03'/>
 <source network='default'/>
 <model type='rtl8139'/>
 </interface>
 </devices>
 </domain>

MACHINE READABLE OUTPUT

The --machine-readable option can be used to make the output more machine friendly, which is useful when calling virt-v2v from other programs, GUIs etc.

There are two ways to use this option.

Firstly use the option on its own to query the capabilities of the virt-v2v binary. Typical output looks like this:

 $ virt-v2v --machine-readable
 virt-v2v
 libguestfs-rewrite
 input:disk
 [...]
 output:local
 [...]
 convert:enterprise-linux
 convert:windows

A list of features is printed, one per line, and the program exits with status 0.

The and features refer to -i and -o (input and output mode) options supported by this binary. The features refer to guest types that this binary knows how to convert.

Secondly use the option in conjunction with other options to make the regular program output more machine friendly.

At the moment this means:

1.

Progress bar messages can be parsed from stdout by looking for this regular expression:

 ^[0-9]+/[0-9]+$

2.

The calling program should treat messages sent to stdout (except for progress bar messages) as status messages. They can be logged and/or displayed to the user.

3.

The calling program should treat messages sent to stderr as error messages. In addition, virt-v2v exits with a non-zero status code if there was a fatal error.

Virt-v2v ≤ 0.9.1 did not support the --machine-readable option at all. The option was added when virt-v2v was rewritten in 2014.

FILES

/usr/share/virtio-win: (Optional)
If this directory is present, then virtio drivers for Windows guests will be found from this directory and installed in the guest during conversion.

ENVIRONMENT VARIABLES

"TMPDIR"

Location of the temporary directory used for the potentially large temporary overlay file.

See the ``Disk space'' section above.

"VIRT_TOOLS_DATA_DIR"

This can point to the directory containing data files used for Windows conversion.

Normally you do not need to set this. If not set, a compiled-in default will be used (something like /usr/share/virt-tools).

This directory may contain the following files:

rhsrvany.exe

(Required when doing conversions of Windows guests)

This is the RHSrvAny Windows binary, used to install a ``firstboot'' script in the guest during conversion of Windows guests.

OTHER TOOLS

virt-v2v-copy-to-local(1): There are some special cases where virt-v2v cannot directly access the remote hypervisor. In that case you have to use virt-v2v-copy-to-local(1) to make a local copy of the guest first, followed by running to perform the conversion.
engine-image-uploader(8): Variously called , or , this tool allows you to copy a guest from one oVirt or Export Storage Domain to another. It only permits importing a guest that was previously exported from another oVirt/RHEV instance.
import-to-ovirt.pl: This script can be used to import guests that already run on to oVirt or For more information, see this blog posting by the author of virt-v2v:
https://rwmj.wordpress.com/2015/09/18/importing-kvm-guests-to-ovirt-or-rhev/#content

AUTHORS

Richard W.M. Jones http://people.redhat.com/~rjones/

Matthew Booth

Mike Latimer

Pino Toscano

Shahar Havivi

Tingting Zheng

COPYRIGHT

LICENSE

This program is free software; you can redistribute it and/or modify it under the terms of the General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but ; without even the implied warranty of or See the General Public License for more details.

You should have received a copy of the General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

BUGS

To get a list of bugs against libguestfs, use this link: https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools

To report a new bug against libguestfs, use this link: https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools

When reporting a bug, please supply:

The version of libguestfs.
Where you got libguestfs (eg. which Linux distro, compiled from source, etc)
Describe the bug accurately and give a way to reproduce it.
Run libguestfs-test-tool(1) and paste the complete, unedited output into the bug report.

URL: https://manpages.org/virt-v2v

⇱ man virt-v2v (1): Convert a guest to use KVM

SYNOPSIS

DESCRIPTION

INPUT AND OUTPUT MODES

EXAMPLES

Convert from VMware vCenter server to local libvirt

Convert from VMware to RHEV-M/oVirt

Convert disk image to OpenStack glance

Convert disk image to disk image

SUPPORT MATRIX

Hypervisors (Input)

Hypervisors (Output)

Virtualization management systems (Output)

Guests

Guest firmware

OPTIONS

XEN PARAVIRTUALIZED GUESTS

ENABLING VIRTIO

RHEL 4

SELinux relabel appears to hang forever

WINDOWS

Windows ≥ 8 Fast Startup is incompatible with virt-v2v

Boot failure: 0x0000007B

OpenStack and Windows reactivation

UEFI

NETWORKS AND BRIDGES

INPUT FROM VMWARE VCENTER SERVER

NON-ADMINISTRATOR

INPUT FROM VMWARE OVA

INPUT FROM VMWARE ESXi HYPERVISOR

ESXi:

ESXi:

ESXi: ESXi

ESXi:

ESXi:

ESXi:

INPUT FROM RHEL 5 XEN

SSH-AGENT

OUTPUT TO LIBVIRT

OUTPUT TO RHEV

OUTPUT TO GLANCE

Glance and sparseness

Glance and multiple disks

Importing disks into Cinder

RESOURCE REQUIREMENTS

Network

Disk space

VMware vCenter resources

Compute power and

POST-CONVERSION TASKS

Guest network configuration

Converting a Windows guest

FREE SPACE FOR CONVERSION

RUNNING VIRT-V2V AS ROOT OR NON-ROOT

DEBUGGING RHEV-M IMPORT FAILURES

MINIMAL XML FOR -i libvirtxml OPTION

MACHINE READABLE OUTPUT

FILES

ENVIRONMENT VARIABLES

OTHER TOOLS

AUTHORS

COPYRIGHT

LICENSE

BUGS

TRANSLATIONS

SEE ALSO

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