
=head1 名前

virt-v2v - Convert a guest to use KVM

=head1 書式

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

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

 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

=head1 説明

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

There is also a companion front-end called L<virt-p2v(1)> which comes as an
ISO, CD or PXE 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
E<ge> 1.28.

=head1 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 rhv
                          └────────────┘ └──────────▶ -o vdsm

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

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

I<-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, RHEL 5 Xen and more.  The I<-ic> option selects the precise
libvirt source.

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

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

I<-o glance> is used for writing to OpenStack Glance.

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

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

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

I<-o rhv> is used to write to a RHV / oVirt target.  I<-o vdsm> is only used
when virt-v2v runs under VDSM control.

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

=head1 例

=head2 Convert from VMware vCenter server to local libvirt

You have a VMware vCenter server called C<vcenter.example.com>, a datacenter
called C<Datacenter>, and an ESXi hypervisor called C<esxi>.  You want to
convert a guest called C<vmware_guest> 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 C<root>, since it
needs to talk to the system libvirt daemon and copy the guest disks to
F</var/lib/libvirt/images>.

For more information see L</INPUT FROM VMWARE VCENTER SERVER> below.

=head2 Convert from VMware to RHV/oVirt

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

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

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

Note that after conversion, the guest will appear in the RHV-M Export
Storage Domain, from where you will need to import it using the RHV-M user
interface.  (See L</OUTPUT TO RHV>).

=head2 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 L</OUTPUT TO GLANCE> below.

=head2 Convert disk image to disk image

Given a disk image from another hypervisor that you want to convert to run
on KVM, 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 F<disk.img> and (in this
case) writes the converted result to F</var/tmp>.

A more complex method is to write some L<libvirt
XML|http://libvirt.org/formatdomain.html> describing the input guest (if you
can get the source hypervisor to provide you with libvirt XML, then so much
the better).  You can then do:

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

Since F<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

=head1 SUPPORT MATRIX

=head2 Hypervisors (Input)

=over 4

=item VMware ESXi

Must be managed by VMware vCenter E<ge> 5.0.  Unmanaged, direct input from
ESXi is not supported.

=item OVA exported from VMware

OVAs from other hypervisors will not work.

=item RHEL 5 Xen

=item SUSE Xen

=item Citrix Xen

Citrix Xen has not been recently tested.

=item Hyper-V

Not recently tested.  Requires that you export the disk or use
L<virt-p2v(1)> on Hyper-V.

=item Direct from disk images

Only disk images exported from supported hypervisors, and using container
formats supported by qemu.

=item Physical machines

Using the L<virt-p2v(1)> tool.

=back

=head2 Hypervisors (Output)

QEMU and KVM only.

=head2 Virtualization management systems (Output)

=over 4

=item OpenStack Glance

=item Red Hat Virtualization (RHV) 4.1 and up

=item Local libvirt

And hence L<virsh(1)>, L<virt-manager(1)>, and similar tools.

=item Local disk

=back

=head2 Guests

=over 4

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

=item CentOS 3, 4, 5, 6, 7

=item Scientific Linux 3, 4, 5, 6, 7

=item Oracle Linux

=item Fedora

=item SLES 10 and up

=item OpenSUSE 10 and up

=item Debian 6 and up

=item Ubuntu 10.04, 12.04, 14.04, 16.04, and up

=item Windows XP to Windows 8.1 / Windows Server 2012 R2

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

Currently NT 5.2 to NT 6.3 are supported.

See L</WINDOWS> below for additional notes on converting Windows guests.

=back

=head2 Guest firmware

BIOS or UEFI for all guest types (but see L</UEFI> below).

=head1 オプション

=over 4

=item B<--help>

ヘルプを表示します。

=item B<-b> ...

=item B<--bridge> ...

See I<--network> below.

=item B<--colors>

=item B<--colours>

Use ANSI colour sequences to colourize messages.  This is the default when
the output is a tty.  If the output of the program is redirected to a file,
ANSI colour sequences are disabled unless you use this option.

=item B<--compressed>

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

=item B<--dcpath> Folder/Datacenter

B<NB:> You don't need to use this parameter if you have S<libvirt E<ge>
1.2.20>.

For VMware vCenter, override the C<dcPath=...> parameter used to select the
datacenter.  Virt-v2v can usually calculate this from the C<vpx://> URI, but
if it gets it wrong, then you can override it using this setting.  Go to
your vCenter web folder interface, eg.
C<https://vcenter.example.com/folder> (I<without> a trailing slash), and
examine the C<dcPath=> parameter in the URLs that appear on this page.

=item B<--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.

=item B<-i> B<disk>

Set the input method to I<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<-i
libvirtxml> instead.  Only guests that use a single disk can be imported
this way.

=item B<-i> B<libvirt>

Set the input method to I<libvirt>.  This is the default.

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

=item B<-i> B<libvirtxml>

Set the input method to I<libvirtxml>.

In this mode you have to pass a libvirt XML 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 L</MINIMAL
XML FOR -i libvirtxml OPTION> below.

=item B<-i> B<local>

This is the same as I<-i disk>.

=item B<-i> B<ova>

Set the input method to I<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 L</INPUT FROM
VMWARE OVA> below

=item B<-ic> libvirtURI

Specify a libvirt connection URI to use when reading the guest.  This is
only used when S<I<-i libvirt>>.

Only local libvirt connections, VMware vCenter connections, or RHEL 5 Xen
remote connections can be used.  Other remote libvirt connections will not
work in general.

See also L</INPUT FROM VMWARE VCENTER SERVER>, L</INPUT FROM XEN> below.

=item B<-if> format

For I<-i disk> only, this specifies the format of the input disk image.  For
other input methods you should specify the input format in the metadata.

=item B<--in-place>

Do not create an output virtual machine in the target hypervisor.  Instead,
adjust the guest OS in the source VM to run in the input hypervisor.

This mode is meant for integration with other toolsets, which take the
responsibility of converting the VM configuration, providing for rollback in
case of errors, transforming the storage, etc.

See L</IN PLACE CONVERSION> below.

Conflicts with all I<-o *> options.

=item B<--machine-readable>

このオプションは、他のプログラムにより解析されるときに、よりマシンに易しい出力を作成するために使用されます。以下の L</マシン可読な出力> 参照。

=item B<-n> in:out

=item B<-n> out

=item B<--network> in:out

=item B<--network> out

=item B<-b> in:out

=item B<-b> out

=item B<--bridge> in:out

=item B<--bridge> out

Map network (or bridge) called C<in> to network (or bridge) called C<out>.
If no C<in:> prefix is given, all other networks (or bridges)  are mapped to
C<out>.

See L</NETWORKS AND BRIDGES> below.

=item B<--no-copy>

Don't copy the disks.  Instead, conversion is performed (and thrown away),
and metadata is written, but no disks are created.  See also discussion of
S<I<-o null>> below.

This is useful in two cases: Either you want to test if conversion is likely
to succeed, without the long copying process.  Or you are only interested in
looking at the metadata.

This option is not compatible with I<-o libvirt> since it would create a
faulty guest (one with no disks).

This option is not compatible with I<-o glance> for technical reasons.

=item B<-o> B<disk>

This is the same as I<-o local>.

=item B<-o> B<glance>

Set the output method to OpenStack Glance.  In this mode the converted guest
is uploaded to Glance.  See L</OUTPUT TO GLANCE> below.

=item B<-o> B<libvirt>

Set the output method to I<libvirt>.  This is the default.

In this mode, the converted guest is created as a libvirt guest.  You may
also specify a libvirt connection URI (see I<-oc>).

See L</OUTPUT TO LIBVIRT> below.

=item B<-o> B<local>

Set the output method to I<local>.

In this mode, the converted guest is written to a local directory specified
by I<-os /dir> (the directory must exist).  The converted guest's disks are
written as:

 /dir/name-sda
 /dir/name-sdb
 [etc]

and a libvirt XML file is created containing guest metadata:

 /dir/name.xml

where C<name> is the guest name.

=item B<-o> B<null>

Set the output method to I<null>.

The guest is converted and copied (unless you also specify I<--no-copy>),
but the results are thrown away and no metadata is written.

=item B<-o> B<ovirt>

This is the same as I<-o rhv>.

=item B<-o> B<qemu>

Set the output method to I<qemu>.

This is similar to I<-o local>, except that a shell script is written which
you can use to boot the guest in qemu.  The converted disks and shell script
are written to the directory specified by I<-os>.

When using this output mode, you can also specify the I<--qemu-boot> option
which boots the guest under qemu immediately.

=item B<-o> B<rhev>

This is the same as I<-o rhv>.

=item B<-o> B<rhv>

Set the output method to I<rhv>.

The converted guest is written to a RHV Export Storage Domain.  The I<-os>
parameter must also be used to specify the location of the Export Storage
Domain.  Note this does not actually import the guest into RHV.  You have to
do that manually later using the UI.

See L</OUTPUT TO RHV> below.

=item B<-o> B<vdsm>

Set the output method to I<vdsm>.

This mode is similar to I<-o rhv>, but the full path to the data domain must
be given:
F</rhv/data-center/E<lt>data-center-uuidE<gt>/E<lt>data-domain-uuidE<gt>>.
This mode is only used when virt-v2v runs under VDSM control.

=item B<-oa> B<sparse>

=item B<-oa> B<preallocated>

Set the output file allocation mode.  The default is C<sparse>.

=item B<-oc> libvirtURI

Specify a libvirt connection to use when writing the converted guest.  This
is only used when S<I<-o libvirt>>.  See L</OUTPUT TO LIBVIRT> below.

Only local libvirt connections can be used.  Remote libvirt connections will
not work.

=item B<-of> format

When converting the guest, convert the disks to the given format.

If not specified, then the input format is used.

=item B<-on> name

Rename the guest when converting it.  If this option is not used then the
output name is the same as the input name.

=item B<-os> storage

The location of the storage for the converted guest.

For I<-o libvirt>, this is a libvirt directory pool (see S<C<virsh
pool-list>>) or pool UUID.

For I<-o local> and I<-o qemu>, this is a directory name.  The directory
must exist.

For I<-o rhv>, this can be an NFS path of the Export Storage Domain of the
form C<E<lt>hostE<gt>:E<lt>pathE<gt>>, eg:

 rhv-storage.example.com:/rhv/export

The NFS export must be mountable and writable by the user and host running
virt-v2v, since the virt-v2v program has to actually mount it when it runs.
So you probably have to run virt-v2v as C<root>.

B<Or:> You can mount the Export Storage Domain yourself, and point I<-os> to
the mountpoint.  Note that virt-v2v will still need to write to this remote
directory, so virt-v2v will still need to run as C<root>.

You will get an error if virt-v2v is unable to mount/write to the Export
Storage Domain.

=item B<--password-file> file

Instead of asking for password(s) interactively, pass the password through a
file.  Note the file should contain the whole password, B<without any
trailing newline>, and for security the file should have mode C<0600> so
that others cannot read it.

=item B<--print-source>

Print information about the source guest and stop.  This option is useful
when you are setting up network and bridge maps.  See L</NETWORKS AND
BRIDGES>.

=item B<--qemu-boot>

When using I<-o qemu> only, this boots the guest immediately after virt-v2v
finishes.

=item B<-q>

=item B<--quiet>

This disables progress bars and other unnecessary output.

=item B<--root ask>

=item B<--root single>

=item B<--root first>

=item B<--root> /dev/sdX

=item B<--root> /dev/VG/LV

Choose the root filesystem to be converted.

In the case where the virtual machine is dual-boot or multi-boot, or where
the VM has other filesystems that look like operating systems, this option
can be used to select the root filesystem (a.k.a. C<C:> drive or F</>) of
the operating system that is to be converted.  The Windows Recovery Console,
certain attached DVD drives, and bugs in libguestfs inspection heuristics,
can make a guest look like a multi-boot operating system.

The default in virt-v2v E<le> 0.7.1 was S<I<--root single>>, which causes
virt-v2v to die if a multi-boot operating system is found.

Since virt-v2v E<ge> 0.7.2 the default is now S<I<--root ask>>: If the VM is
found to be multi-boot, then virt-v2v will stop and list the possible root
filesystems and ask the user which to use.  This requires that virt-v2v is
run interactively.

S<I<--root first>> means to choose the first root device in the case of a
multi-boot operating system.  Since this is a heuristic, it may sometimes
choose the wrong one.

You can also name a specific root device, eg. S<I<--root /dev/sda2>> would
mean to use the second partition on the first hard drive.  If the named root
device does not exist or was not detected as a root device, then virt-v2v
will fail.

Note that there is a bug in grub which prevents it from successfully booting
a multiboot system if VirtIO is enabled.  Grub is only able to boot an
operating system from the first VirtIO disk.  Specifically, F</boot> must be
on the first VirtIO disk, and it cannot chainload an OS which is not in the
first VirtIO disk.

=item B<--vdsm-compat=0.10>

=item B<--vdsm-compat=1.1>

If I<-o vdsm> and the output format is qcow2, then we add the qcow2
I<compat=0.10> option to the output file for compatibility with RHEL 6 (see
L<https://bugzilla.redhat.com/1145582>).

If I<--vdsm-compat=1.1> is used then modern qcow2 (I<compat=1.1>)  files are
generated instead.

Currently I<--vdsm-compat=0.10> is the default, but this will change to
I<--vdsm-compat=1.1> in a future version of virt-v2v (when we can assume
that everyone is using a modern version of qemu).

B<Note this option only affects I<-o vdsm> output>.  All other output modes
(including I<-o rhv>) generate modern qcow2 I<compat=1.1> files, always.

=item B<--vdsm-image-uuid> UUID

=item B<--vdsm-vol-uuid> UUID

=item B<--vdsm-vm-uuid> UUID

=item B<--vdsm-ovf-output>

Normally the RHV output mode chooses random UUIDs for the target guest.
However VDSM needs to control the UUIDs and passes these parameters when
virt-v2v runs under VDSM control.  The parameters control:

=over 4

=item *

the image directory of each guest disk (I<--vdsm-image-uuid>) (this option
is passed once for each guest disk)

=item *

UUIDs for each guest disk (I<--vdsm-vol-uuid>) (this option is passed once
for each guest disk)

=item *

the OVF file name (I<--vdsm-vm-uuid>).

=item *

the OVF output directory (default current directory) (I<--vdsm-ovf-output>).

=back

The format of UUIDs is: C<12345678-1234-1234-1234-123456789abc> (each hex
digit can be C<0-9> or C<a-f>), conforming to S<OSF DCE 1.1>.

These options can only be used with I<-o vdsm>.

=item B<-v>

=item B<--verbose>

デバッグ用の冗長なメッセージを有効にします。

=item B<-V>

=item B<--version>

バージョン番号を表示して、終了します。

=item B<-x>

libguestfs API 呼び出しのトレースを有効にします。

=back

=head1 XEN PARAVIRTUALIZED GUESTS

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

=head1 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 KVM.

Older versions of virt-v2v could install these drivers for certain Linux
guests.  This version of virt-v2v does I<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 B<minimum> versions of packages are
installed I<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

 Debian 6+      All versions support virtio

 Ubuntu 10.04+  All versions support virtio

 Windows        Drivers are installed from the directory pointed to by
                "VIRTIO_WIN" environment variable
                (/usr/share/virtio-win by default) if present

=head1 RHEL 4

=head2 SELinux relabel appears to hang forever

In RHEL E<le> 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 C<[Return]> key, at which point
the guest will finish relabelling and reboot, or you can install
policycoreutils E<ge> 1.18.1-4.13 before starting the v2v conversion.  See
also L<https://bugzilla.redhat.com/show_bug.cgi?id=244636>

=head1 DEBIAN AND UBUNTU

=head2 "warning: could not determine a way to update the configuration of Grub2"

Currently, virt-v2v has no way to set the default kernel in Debian and
Ubuntu guests using GRUB 2 as bootloader.  This means that virt-v2v will not
change the default kernel used for booting, even in case it is not the best
kernel available on the guest.  A recommended procedure is, before using
virt-v2v, to check that the boot kernel is the best kernel available in the
guest (for example by making sure the guest is up-to-date).

=head1 WINDOWS

=head2 Windows E<ge> 8 Fast Startup is incompatible with virt-v2v

Guests which use the Windows E<ge> 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: L<guestfs(3)/WINDOWS HIBERNATION AND WINDOWS 8
FAST STARTUP>.

=head2 Boot failure: 0x0000007B

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

=over 4

=item *

First ensure that the guest boots on the source hypervisor before
conversion.

=item *

Check you have the Windows virtio drivers available in
F</usr/share/virtio-win>, and that virt-v2v did not print any warning about
not being able to install virtio drivers.

On S<Red Hat Enterprise Linux 7>, you will need to install the signed
drivers available in the C<virtio-win> package.  If you do not have access
to the signed drivers, then you will probably need to disable driver signing
in the boot menus.

=item *

Check that you are presenting a virtio-blk interface (B<not> virtio-scsi and
B<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 XML, you should see:

 <target dev='vda' bus='virtio'/>

=item *

Check that Windows Group Policy does not prevent the driver from being
installed or used.  Try deleting Windows Group Policy before conversion.

=item *

Check there is no anti-virus or other software which implements Group
Policy-like prohibitions on installing or using new drivers.

=item *

Enable boot debugging and check the F<viostor.sys> driver is being loaded.

=back

=head2 OpenStack and Windows reactivation

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

=over 4

=item *

A new disk or network device has been added or removed from the guest.

=item *

The version of OpenStack or (possibly) libvirt has changed.

=back

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 C<Device Installation Restrictions>.

=head1 UEFI

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

Currently KVM supports OVMF, an open source UEFI firmware, and can run these
guests.

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

=over 4

=item UEFI on libvirt, qemu

Supported.  Virt-v2v will generate the correct libvirt XML (metadata)
automatically, but note that the same version of OVMF 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 RHEL E<ge> 7.3, only qemu-kvm-rhev (not qemu-kvm) is supported.

=item UEFI on OpenStack

Not supported.

=item UEFI on RHV

Not supported.

=back

=head1 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 I<--network> and I<--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 XML, vCenter
information, etc.).  Or you can run virt-v2v with the I<--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 I<--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 C<default>.

To map a specific network to a target network, for example C<default> on the
source to C<ovirtmgmt> on the target, use:

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

To map every network to a target network, use:

 virt-v2v [...] --network ovirtmgmt

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

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

=head1 INPUT FROM VMWARE VCENTER SERVER

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

vCenter E<ge> 5.0 is required.  If you don't have vCenter, using OVA is
recommended instead (see L</INPUT FROM VMWARE OVA> below), or if that is not
possible then see L</INPUT FROM VMWARE ESXi HYPERVISOR>.

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

=head2 VCENTER: REMOVE VMWARE TOOLS FROM WINDOWS GUESTS

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.

=head2 VCENTER: URI

The libvirt URI of a vCenter server looks something like this:

 vpx://user@server/Datacenter/esxi

where:

=over 4

=item C<user@>

is the (optional, but recommended) user to connect as.

If the username contains a backslash (eg. C<DOMAIN\USER>) then you will need
to URI-escape that character using C<%5c>: C<DOMAIN%5cUSER> (5c is the
hexadecimal ASCII code for backslash.)  Other punctuation may also have to
be escaped.

=item C<server>

is the vCenter Server (I<not> hypervisor).

=item C<Datacenter>

is the name of the datacenter.

If the name contains a space, replace it with the URI-escape code C<%20>.

=item C<esxi>

is the name of the ESXi hypervisor running the guest.

=back

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

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

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

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

=over 4

=item *

Could not find datacenter specified in [...]

=item *

Could not find compute resource specified in [...]

=item *

Path [...] does not specify a compute resource

=item *

Path [...] does not specify a host system

=item *

Could not find host system specified in [...]

=back

=head2 VCENTER: TEST LIBVIRT CONNECTION TO VCENTER

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

 $ virsh -c 'vpx://root@vcenter.example.com/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 CA
certificates" or similar, then you can either import the vCenter host's
certificate, or bypass signature verification by adding the C<?no_verify=1>
flag:

 $ virsh -c 'vpx://root@vcenter.example.com/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://root@vcenter.example.com/Datacenter/esxi' dumpxml "Windows 2003"
 <domain type='vmware'>
   <name>Windows 2003</name>
   [...]
 </domain>

B<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.

=head2 VCENTER: IMPORTING A GUEST

To import a particular guest from vCenter Server, do:

 $ virt-v2v -ic 'vpx://root@vcenter.example.com/Datacenter/esxi?no_verify=1' \
   "Windows 2003" \
   -o local -os /var/tmp

where C<Windows 2003> is the name of the guest (which must be shut down).

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

=head2 VCENTER: NON-ADMINISTRATOR ROLE

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:

=over 4

=item 1.

Create a custom role in vCenter.

=item 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

=back

=head2 VCENTER: FIREWALL AND PROXY SETTINGS

=head3 vCenter: Ports

If there is a firewall between the virt-v2v conversion server and the
vCenter server, then you will need to open port 443 (https) and port 5480.

Port 443 is used to copy the guest disk image(s).  Port 5480 is used to
query vCenter for guest metadata.

These port numbers are only the defaults.  It is possible to reconfigure
vCenter to use other port numbers.  In that case you would need to specify
those ports in the C<vpx://> URI.  See L</VCENTER: URI> above.

These ports only apply to virt-v2v conversions.  You may have to open other
ports for other vCenter functionality, for example the web user interface.
VMware documents the required ports for vCenter in their online
documentation.

 ┌────────────┐   port 443 ┌────────────┐        ┌────────────┐
 │ virt-v2v   │────────────▶ vCenter    │────────▶ ESXi       │
 │ conversion │────────────▶ server     │        │ hypervisor │
 │ server     │  port 5480 │            │        │   ┌─────┐  │
 └────────────┘            └────────────┘        │   │guest│  │
                                                 └───┴─────┴──┘

(In the diagram above the arrows show the direction in which the TCP
connection is initiated, I<not> necessarily the direction of data transfer.)

Virt-v2v itself does not connect directly to the ESXi hypervisor containing
the guest.  However vCenter connects to the hypervisor and forwards the
information, so if you have a firewall between vCenter and its hypervisors
you may need to open additional ports (consult VMware documentation).

The proxy environment variables (C<https_proxy>, C<all_proxy>, C<no_proxy>,
C<HTTPS_PROXY>, C<ALL_PROXY> and C<NO_PROXY>) are B<ignored> when doing
vCenter conversions.

=head1 INPUT FROM VMWARE OVA

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

=head2 OVA: REMOVE VMWARE TOOLS FROM WINDOWS GUESTS

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.

=head2 OVA: CREATE OVA

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

=head3 Create OVA with ovftool

You can also use VMware's proprietary C<ovftool>:

 ovftool --noSSLVerify \
   vi://USER:PASSWORD@esxi.example.com/VM \
   VM.ova

To connect to vCenter:

 ovftool  --noSSLVerify \
   vi://USER:PASSWORD@vcenter.example.com/DATACENTER-NAME/vm/VM \
   VM.ova

For Active Directory-aware authentication, you have to express the C<@>
character in the form of its ascii hex-code (C<%5c>):

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

=head2 OVA: IMPORTING A GUEST

To import an OVA file called F<VM.ova>, do;

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

If you exported the guest as a "Folder of files", I<or> if you unpacked the
OVA 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

=head1 INPUT FROM VMWARE ESXi HYPERVISOR

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

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

=head2 ESXi: REMOVE VMWARE TOOLS FROM WINDOWS GUESTS

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.

=head2 ESXi: URI

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

 esx://root@esxi.example.com?no_verify=1

The C<?no_verify=1> parameter disables TLS certificate checking.

=head2 ESXi: TEST LIBVIRT CONNECTION TO ESXi HYPERVISOR

Use the L<virsh(1)> command to test the URI and list the remote guests
available:

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

=head2 ESXi: COPY THE GUEST TO THE LOCAL MACHINE

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

 $ virt-v2v-copy-to-local -ic esx://root@esxi.example.com?no_verify=1 guest

This creates F<guest.xml>, F<guest-disk1>, ...

=head2 ESXi: DO THE VIRT-V2V CONVERSION

Perform the conversion of the guest using virt-v2v:

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

=head2 ESXi: CLEAN UP

Remove the F<guest.xml> and F<guest-disk*> files.

=head1 INPUT FROM XEN

Virt-v2v is able to import Xen guests from RHEL 5 Xen or SLES and openSUSE
Xen hosts.

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

=head2 XEN: SET UP SSH-AGENT ACCESS TO XEN HOST

Currently you must enable passwordless SSH 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
F</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 root@xen.example.com
 [ logs straight into the shell, no password is requested ]

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

=head2 XEN: TEST LIBVIRT CONNECTION TO REMOTE XEN HOST

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

 $ virsh -c xen+ssh://root@xen.example.com 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://root@xen.example.com dumpxml rhel49-x86_64-pv
 <domain type='xen'>
   <name>rhel49-x86_64-pv</name>
   [...]
 </domain>

B<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.

B<If the guest disks are located on a host block device>, then the
conversion will fail.  See L</XEN OR SSH CONVERSIONS FROM BLOCK DEVICES>
below for a workaround.

=head2 XEN: IMPORTING A GUEST

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

 $ LIBGUESTFS_BACKEND=direct \
       virt-v2v -ic 'xen+ssh://root@xen.example.com' \
           rhel49-x86_64-pv \
           -o local -os /var/tmp

where C<rhel49-x86_64-pv> 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.

Setting the L<backend|guestfs(3)/BACKEND> to C<direct> is a temporary
workaround until L<libvirt bug 1140166|https://bugzilla.redhat.com/1140166>
is fixed.

=head2 XEN OR SSH CONVERSIONS FROM BLOCK DEVICES

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 XML.  You
will see:

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

where C<type='block'>, C<source dev=> and C</dev/...> 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 L<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://root@xen.example.com guest
 virt-v2v -i libvirtxml guest.xml -o local -os /var/tmp
 rm guest.xml guest-disk*

=head1 OUTPUT TO LIBVIRT

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

=over 4

=item *

You can only use a local libvirt connection [see below for how to workaround
this].

=item *

The I<-os pool> option must specify a directory pool, not anything more
exotic such as iSCSI [but see below].

=item *

You can only upload to a KVM hypervisor.

=back

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

=over 4

=item 1.

Use virt-v2v in I<-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 F</var/tmp> called:

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

(for C<NAME> substitute the guest's name).

=item 2.

Upload the converted disk(s) into the storage pool called C<POOL>:

 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

=item 3.

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

 <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 C<type='file'> attribute must be changed to
C<type='volume'>, and the C<E<lt>sourceE<gt>> element must be changed to
include C<pool> and C<volume> attributes:

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

=item 4.

Define the final guest in libvirt:

 virsh define /var/tmp/NAME.xml

=back

=head1 OUTPUT TO RHV

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

You have to specify I<-o rhv> and an I<-os> option that points to the RHV-M
Export Storage Domain.  You can either specify the NFS server and
mountpoint, eg. S<C<-os rhv-storage:/rhv/export>>, or you can mount that
first and point to the directory where it is mounted, eg. S<C<-os
/tmp/mnt>>.  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 RHV using the UI before it can be used.

In RHV E<ge> 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 "VM Import".  The
converted guest will be listed here.  Select the appropriate guest an click
"Import".  See the RHV documentation for additional details.

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

=head1 OUTPUT TO GLANCE

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

This runs the L<glance(1)> CLI program which must be installed on the
virt-v2v conversion host.  For authentication to work, you will need to set
C<OS_*> environment variables.  In most cases you can do this by sourcing a
file called something like F<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
C<glance image-show> will display the metadata as "Property" fields such as
C<os_type> and C<hw_disk_bus>.

=head2 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 S<I<-of qcow2>> option.

=head2 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 I<-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 C<I<guestname>-disk2>, C<I<guestname>-disk3> etc.
It may be best to leave the system disk in Glance, and import the data disks
to Cinder (see next section).

=head2 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
(L<https://bugzilla.redhat.com/1155229>).  There are two ways to upload to
Cinder:

=over 4

=item 1.

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

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

=item 2.

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

 cinder manage <VOLUMEREF>

=back

=head1 RESOURCE REQUIREMENTS

=head2 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, NFS
server, vCenter, Xen) are as fast and as low latency as possible.

=head2 Disk space

Virt-v2v places potentially large temporary files in C<$TMPDIR> (which is
F</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.

=over 4

=item I<-i ova>

This temporarily places a full copy of the uncompressed source disks in
C<$TMPDIR>.

=item I<-o glance>

This temporarily places a full copy of the output disks in C<$TMPDIR>.

=item I<-o local>

=item I<-o qemu>

You must ensure there is sufficient space in the output directory for the
converted guest.

=item I<-o null>

This temporarily places a full copy of the output disks in C<$TMPDIR>.

=back

See also L</Minimum free space check in the host> below.

=head2 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.

=head2 Compute power and RAM

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

Virt-v2v can be run in a virtual machine.

=head2 Trimming

Virt-v2v attempts to optimize the speed of conversion by ignoring guest
filesystem data which is not used.  This would include unused filesystem
blocks, blocks containing zeroes, and deleted files.

To do this, virt-v2v issues a non-destructive L<fstrim(8)> operation.  As
this happens to an overlay placed over the guest data, it does B<not> affect
the source in any way.

If this fstrim operation fails, you will see a warning, but virt-v2v will
continue anyway.  It may run more slowly (in some cases much more slowly),
because it is copying the unused parts of the disk.

Unfortunately support for fstrim is not universal, and it also depends on
specific details of the filesystem, partition alignment, and backing
storage.  As an example, NTFS filesystems cannot be fstrimmed if they occupy
a partition which is not aligned to the underlying storage.  That was the
default on Windows before Vista.  As another example, VFAT filesystems (used
by UEFI guests) cannot be trimmed at all.

fstrim support in the Linux kernel is improving gradually, so over time some
of these restrictions will be lifted and virt-v2v will work faster.

=head1 POST-CONVERSION TASKS

=head2 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
L<virt-customize(1)>.

=head2 Converting a Windows guest

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

=over 

=item 1

Offline conversion.

=item 2

First boot.

=back

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.

B<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.

=head1 FREE SPACE FOR CONVERSION

=head2 Free space in the guest

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

=over 4

=item Linux root filesystem or Windows C<C:> drive

Minimum free space: 20 MB

=item Linux F</boot>

Minimum free space: 50 MB

This is because we need to build a new initramfs for some Enterprise Linux
conversions.

=item Any other mountable filesystem

Minimum free space: 10 MB

=back

=head2 Minimum free space check in the host

You must have sufficient free space in the host directory used to store
temporary overlays (except in I<--in-place> mode).  To find out which
directory this is, use:

 $ df -h "`guestfish get-cachedir`"
 Filesystem        Size  Used Avail Use% Mounted on
 /dev/mapper/root   50G   40G  6.8G  86% /

and look under the C<Avail> column.  Virt-v2v will refuse to do the
conversion at all unless at least 1GB is available there.

See also L</RESOURCE REQUIREMENTS> above.

=head1 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:

=over 4

=item Mounting the Export Storage Domain

When using I<-o rhv -os server:/esd> virt-v2v has to have sufficient
privileges to NFS mount the Export Storage Domain from C<server>.

You can avoid needing root here by mounting it yourself before running
virt-v2v, and passing I<-os /mountpoint> instead, but first of all read the
next S<section ...>

=item Writing to the Export Storage Domain as 36:36

RHV-M cannot read files and directories from the Export Storage Domain
unless they have UID:GID 36:36.  You will see VM import problems if the
UID:GID is not correct.

When you run virt-v2v I<-o rhv> 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.

=item Writing to libvirt

When using I<-o libvirt>, you may need to run virt-v2v as root so that it
can write to the libvirt system instance (ie. C<qemu:///system>)  and to the
default location for disk images (usually F</var/lib/libvirt/images>).

You can avoid this by setting up libvirt connection authentication, see
L<http://libvirt.org/auth.html>.  Alternatively, use I<-oc qemu:///session>,
which will write to your per-user libvirt instance.

=item Writing to Glance

This does I<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.

=back

=head1 DEBUGGING RHV-M IMPORT FAILURES

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

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

The second file, which is the most useful, is found on the SPM host (SPM
stands for "Storage Pool Manager").  This is a RHV 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 SPM from the "Hosts"
tab "Spm Status" column.  Once you have located the SPM, log into it and
grab the file F</var/log/vdsm/vdsm.log> which will contain detailed error
messages from low-level commands.

=head1 MINIMAL XML FOR -i libvirtxml OPTION

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

B<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>

=head1 IN PLACE CONVERSION

It is also possible to use virt-v2v in scenarios where a foreign VM has
already been imported into a KVM-based hypervisor, but still needs
adjustments in the guest to make it run in the new virtual hardware.

In that case it is assumed that a third-party tool has created the target VM
in the supported KVM-based hypervisor based on the source VM configuration
and contents, but using virtual devices more appropriate for KVM
(e.g. virtio storage and network, etc.).

Then, to make the guest OS boot and run in the changed environment, one can
use:

 virt-v2v -ic qemu:///system converted_vm --in-place

Virt-v2v will analyze the configuration of C<converted_vm> in the
C<qemu:///system> libvirt instance, and apply various fixups to the guest OS
configuration to make it match the VM configuration.  This may include
installing virtio drivers, configuring the bootloader, the mountpoints, the
network interfaces, and so on.

Should an error occur during the operation, virt-v2v exits with an error
code leaving the VM in an undefined state.

=head1 マシン可読な出力

The I<--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.

このオプションを使用するには 2 通りの方法があります。

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
 colours-option
 input:disk
 [...]
 output:local
 [...]
 convert:linux
 convert:windows

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

The C<input:> and C<output:> features refer to I<-i> and I<-o> (input and
output mode) options supported by this binary.  The C<convert:> 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:

=over 4

=item 1.

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

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

=item 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.

=item 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.

=back

Virt-v2v E<le> 0.9.1 did not support the I<--machine-readable> option at
all.  The option was added when virt-v2v was rewritten in 2014.

=head1 ファイル

=over 4

=item F</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.

=back

=head1 環境変数

=over 4

=item C<TMPDIR>

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

See the L</Disk space> section above.

=item C<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 F</usr/share/virt-tools>).

This directory may contain the following files:

=over 4

=item F<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.

See also: C<https://github.com/rwmjones/rhsrvany>

=item F<pvvxsvc.exe>

This is a Windows binary shipped with SUSE VMDP, used to install a
"firstboot" script in Windows guests.  It is required if you intend to use
the I<--firstboot> or I<--firstboot-command> options with Windows guests.

=item F<rhev-apt.exe>

(Optional)

The RHV Application Provisioning Tool (RHEV APT).  If this file is present,
then RHEV APT will be installed in the Windows guest during conversion.
This tool is a guest agent which ensures that the virtio drivers remain up
to date when the guest is running on Red Hat Virtualization (RHV).

This file comes from Red Hat Virtualization (RHV), and is not distributed
with virt-v2v.

=back

=item C<VIRTIO_WIN>

This is where VirtIO drivers for Windows are searched for
(F</usr/share/virtio-win> if unset).  It can be a directory I<or> point to
F<virtio-win.iso> (CD ROM image containing drivers).

See L<ENABLING VIRTIO>.

=back

他の環境変数は L<guestfs(3)/環境変数> を参照してください。

=head1 OTHER TOOLS

=over 4

=item L<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
L<virt-v2v-copy-to-local(1)> to make a local copy of the guest first,
followed by running C<virt-v2v -i libvirtxml> to perform the conversion.

=item L<engine-image-uploader(8)>

Variously called C<engine-image-uploader>, C<ovirt-image-uploader> or
C<rhevm-image-uploader>, this tool allows you to copy a guest from one oVirt
or RHV Export Storage Domain to another.  It only permits importing a guest
that was previously exported from another oVirt/RHV instance.

=item L<import-to-ovirt.pl|http://git.annexia.org/?p=import-to-ovirt.git>

This script can be used to import guests that already run on KVM to oVirt or
RHV.  For more information, see this blog posting by the author of virt-v2v:

L<https://rwmj.wordpress.com/2015/09/18/importing-kvm-guests-to-ovirt-or-rhev/#content>

=back

=head1 関連項目

L<virt-p2v(1)>, L<virt-customize(1)>, L<virt-df(1)>, L<virt-filesystems(1)>,
L<virt-sparsify(1)>, L<virt-sysprep(1)>, L<guestfs(3)>, L<guestfish(1)>,
L<qemu-img(1)>, L<virt-v2v-copy-to-local(1)>, L<virt-v2v-test-harness(1)>,
L<engine-image-uploader(8)>,
L<import-to-ovirt.pl|http://git.annexia.org/?p=import-to-ovirt.git>,
L<http://libguestfs.org/>.

=head1 著者

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

Matthew Booth

Mike Latimer

Pino Toscano

Shahar Havivi

Tingting Zheng

=head1 COPYRIGHT

Copyright (C) 2009-2017 Red Hat Inc.

