From f2e233b9e073327b1881ef17695380bc02a51f68 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Thu, 29 Jun 2023 14:34:43 +0200
Subject: [PATCH] docs/virt-v2v: document libvirt system instance startup
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It has frequently tripped us up that on RHEL / Fedora, installing the
right set of libvirt RPMs (such as the one pulled in by
"libvirt-daemon-kvm") does not result in an immediately running libvirt
system instance.  Document the need, and the simplest method, for starting
libvirt up manually.

Thanks: Daniel Berrangé
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2182024
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20230629123443.188350-4-lersek@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
(cherry picked from commit dcfea1b9b5d0f237f49c9eb870af93527093b40b)
---
 docs/virt-v2v.pod | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/docs/virt-v2v.pod b/docs/virt-v2v.pod
index 0394b421..058eb800 100644
--- a/docs/virt-v2v.pod
+++ b/docs/virt-v2v.pod
@@ -237,6 +237,8 @@ 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>).
 
+See L</Starting the libvirt system instance> below.
+
 =item B<-i> B<libvirtxml>
 
 Set the input method to I<libvirtxml>.
@@ -440,7 +442,8 @@ 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<virt-v2v-output-local(1)>.
+See L</Starting the libvirt system instance> below, and
+L<virt-v2v-output-local(1)>.
 
 =item B<-o> B<local>
 
@@ -1335,6 +1338,8 @@ see L<http://libvirt.org/auth.html>.  Alternatively, use
 I<-oc qemu:///session>, which will write to your per-user libvirt
 instance.
 
+See also L</Starting the libvirt system instance>.
+
 =item Writing to Openstack
 
 Because of how Cinder volumes are presented as F</dev> block devices,
@@ -1476,6 +1481,22 @@ option at all.  The option was added when virt-v2v was rewritten in 2014.
 It is possible to specify a format string for controlling the output;
 see L<guestfs(3)/ADVANCED MACHINE READABLE OUTPUT>.
 
+=head2 Starting the libvirt system instance
+
+ Failed to connect socket to '/var/run/libvirt/virtqemud-sock': No such file or directory
+ Failed to connect socket to '/var/run/libvirt/virtqemud-sock-ro': Connection refused
+
+If you have just installed libvirt and virt-v2v, then you may see the
+errors above.  This is caused by libvirt daemons that provide various
+services not running straight after installation.  (This may depend on
+your distribution and vendor presets).
+
+To fix this on systemd-based distributions, do:
+
+ systemctl isolate multi-user.target
+
+See also L<https://bugzilla.redhat.com/2182024>.
+
 =head1 FILES
 
 =over 4