1virt-v2v-input-xen(1) Virtualization Support virt-v2v-input-xen(1)
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6 virt-v2v-input-xen - Using virt-v2v to convert guests from Xen
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9 virt-v2v -ic 'xen+ssh://root@xen.example.com'
10 -ip passwordfile
11 GUEST_NAME [-o* options]
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14 This page documents how to use virt-v2v(1) to convert guests from RHEL
15 5 Xen, or SLES and OpenSUSE Xen hosts.
16
18 SSH authentication
19 You can use SSH password authentication, by supplying the name of a
20 file containing the password to the -ip option (note this option does
21 not take the password directly). You may need to adjust
22 /etc/ssh/sshd_config on the Xen server to set "PasswordAuthentication
23 yes".
24 If you are not using password authentication, an alternative is to use
26 ssh-agent, and add your ssh public key to /root/.ssh/authorized_keys
27 (on the Xen host). After doing this, you should check that
28 passwordless access works from the virt-v2v server to the Xen host.
29 For example:
30 $ ssh root@xen.example.com
32 [ logs straight into the shell, no password is requested ]
33 Note that support for non-interactive authentication via the -ip option
35 is incomplete. Some operations remain that still require the user to
36 enter the password manually. Therefore ssh-agent is recommended over
37 the -ip option. See https://bugzilla.redhat.com/1854275.
38 With some modern ssh implementations, legacy crypto algorithms required
40 to interoperate with RHEL 5 sshd are disabled. To enable them, you may
41 need to add the following "Host" stanza to your ~/.ssh/config:
42 Host xen.example.com
44 KexAlgorithms +diffie-hellman-group14-sha1
45 MACs +hmac-sha1
46 HostKeyAlgorithms +ssh-rsa
47 PubkeyAcceptedKeyTypes +ssh-rsa
48 PubkeyAcceptedAlgorithms +ssh-rsa
49 ("PubkeyAcceptedKeyTypes" and "PubkeyAcceptedAlgorithms" have identical
51 meaning; the former is the old option name, the latter is the new one.
52 Virt-v2v uses both "libssh" and "ssh" when converting a guest from Xen,
53 and on some operating systems, "libssh" and "ssh" may not both accept
54 the same option variant.)
55 When connecting to RHEL 5 sshd from RHEL 9, the SHA1 algorithm's use in
57 signatures has to be re-enabled at the OpenSSL level, in addition to
58 the above SSH configuration. Create a file called
59 $HOME/openssl-sha1.cnf with the following contents:
60 .include /etc/ssl/openssl.cnf
62 [openssl_init]
63 alg_section = evp_properties
64 [evp_properties]
65 rh-allow-sha1-signatures = yes
66 and export the following variable into the environment of the
68 "virt-v2v" process:
69 OPENSSL_CONF=$HOME/openssl-sha1.cnf
71 Note that the "OPENSSL_CONF" environment variable will only take effect
73 if the libvirt client library used by virt-v2v is at least version
74 8.6.0.
75 Test libvirt connection to remote Xen host
77 Use the virsh(1) command to list the guests on the remote Xen host:
78 $ virsh -c xen+ssh://root@xen.example.com list --all
80 Id Name State
81 ----------------------------------------------------
82 0 Domain-0 running
83 - rhel49-x86_64-pv shut off
84 You should also try dumping the metadata from any guest on your server,
86 like this:
87 $ virsh -c xen+ssh://root@xen.example.com dumpxml rhel49-x86_64-pv
89 <domain type='xen'>
90 <name>rhel49-x86_64-pv</name>
91 [...]
92 </domain>
93 If the above commands do not work, then virt-v2v is not going to work
95 either. Fix your libvirt configuration or the remote server before
96 continuing.
97 If the guest disks are located on a host block device, then the
99 conversion will fail. See "Xen or ssh conversions from block devices"
100 below for a workaround.
101 Importing a guest
103 To import a particular guest from a Xen server, do:
104 $ virt-v2v -ic 'xen+ssh://root@xen.example.com' \
106 rhel49-x86_64-pv \
107 -o local -os /var/tmp
108 where "rhel49-x86_64-pv" is the name of the guest (which must be shut
110 down).
111 In this case the output flags are set to write the converted guest to a
113 temporary directory as this is just an example, but you can also write
114 to libvirt or any other supported target.
115 Xen or ssh conversions from block devices
117 Currently virt-v2v cannot directly access a Xen guest (or any guest
118 located remotely over ssh) if that guest’s disks are located on host
119 block devices.
120 To tell if a Xen guest uses host block devices, look at the guest XML.
122 You will see:
123 <disk type='block' device='disk'>
125 ...
126 <source dev='/dev/VG/guest'/>
127 where "type='block'", "source dev=" and "/dev/..." are all indications
129 that the disk is located on a host block device.
130 This happens because the qemu ssh block driver that we use to access
132 remote disks uses the ssh sftp protocol, and this protocol cannot
133 correctly detect the size of host block devices.
134 The workaround is to copy the block device from the remote Xen server
136 to a regular local file, copy the libvirt guest XML, adjust the "disk"
137 element to point to the local file, and use "-i libvirtxml" mode
138 instead.
139
141 virt-v2v(1).
142
144 Richard W.M. Jones
145
147 Copyright (C) 2009-2020 Red Hat Inc.
148
150 This program is free software; you can redistribute it and/or modify it
151 under the terms of the GNU General Public License as published by the
152 Free Software Foundation; either version 2 of the License, or (at your
153 option) any later version.
154 This program is distributed in the hope that it will be useful, but
156 WITHOUT ANY WARRANTY; without even the implied warranty of
157 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
158 General Public License for more details.
159 You should have received a copy of the GNU General Public License along
161 with this program; if not, write to the Free Software Foundation, Inc.,
162 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
163
165 To get a list of bugs against libguestfs, use this link:
166 https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
167 To report a new bug against libguestfs, use this link:
169 https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
170 When reporting a bug, please supply:
172 • The version of libguestfs.
174 • Where you got libguestfs (eg. which Linux distro, compiled from
176 source, etc)
177 • Describe the bug accurately and give a way to reproduce it.
179 • Run libguestfs-test-tool(1) and paste the complete, unedited output
181 into the bug report.
182virt-v2v-2.3.7 2023-12-09 virt-v2v-input-xen(1)