<link>http://people.skolelinux.org/pere/blog/</link>
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+ <item>
+ <title>Migrating Xen virtual machines using LVM to KVM using disk images</title>
+ <link>http://people.skolelinux.org/pere/blog/Migrating_Xen_virtual_machines_using_LVM_to_KVM_using_disk_images.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Migrating_Xen_virtual_machines_using_LVM_to_KVM_using_disk_images.html</guid>
+ <pubDate>Mon, 22 Nov 2010 11:20:00 +0100</pubDate>
+ <description>
+<p>Most of the computers in use by the
+<a href="http://www.skolelinux.org/">Debian Edu/Skolelinux project</a>
+are virtual machines. And they have been Xen machines running on a
+fairly old IBM eserver xseries 345 machine, and we wanted to migrate
+them to KVM on a newer Dell PowerEdge 2950 host machine. This was a
+bit harder that it could have been, because we set up the Xen virtual
+machines to get the virtual partitions from LVM, which as far as I
+know is not supported by KVM. So to migrate, we had to convert
+several LVM logical volumes to partitions on a virtual disk file.</p>
+
+<p>I found
+<a href="http://searchnetworking.techtarget.com.au/articles/35011-Six-steps-for-migrating-Xen-virtual-machines-to-KVM">a
+nice recipe</a> to do this, and wrote the following script to do the
+migration. It uses qemu-img from the qemu package to make the disk
+image, parted to partition it, losetup and kpartx to present the disk
+image partions as devices, and dd to copy the data. I NFS mounted the
+new servers storage area on the old server to do the migration.</p>
+
+<pre>
+#!/bin/sh
+
+# Based on
+# http://searchnetworking.techtarget.com.au/articles/35011-Six-steps-for-migrating-Xen-virtual-machines-to-KVM
+
+set -e
+set -x
+
+if [ -z "$1" ] ; then
+ echo "Usage: $0 &lt;hostname&gt;"
+ exit 1
+else
+ host="$1"
+fi
+
+if [ ! -e /dev/vg_data/$host-disk ] ; then
+ echo "error: unable to find LVM volume for $host"
+ exit 1
+fi
+
+# Partitions need to be a bit bigger than the LVM LVs. not sure why.
+disksize=$( lvs --units m | grep $host-disk | awk '{sum = sum + $4} END { print int(sum * 1.05) }')
+swapsize=$( lvs --units m | grep $host-swap | awk '{sum = sum + $4} END { print int(sum * 1.05) }')
+totalsize=$(( ( $disksize + $swapsize ) ))
+
+img=$host.img
+#dd if=/dev/zero of=$img bs=1M count=$(( $disksize + $swapsize ))
+qemu-img create $img ${totalsize}MMaking room on the Debian Edu/Sqeeze DVD
+
+parted $img mklabel msdos
+parted $img mkpart primary linux-swap 0 $disksize
+parted $img mkpart primary ext2 $disksize $totalsize
+parted $img set 1 boot on
+
+modprobe dm-mod
+losetup /dev/loop0 $img
+kpartx -a /dev/loop0
+
+dd if=/dev/vg_data/$host-disk of=/dev/mapper/loop0p1 bs=1M
+fsck.ext3 -f /dev/mapper/loop0p1 || true
+mkswap /dev/mapper/loop0p2
+
+kpartx -d /dev/loop0
+losetup -d /dev/loop0
+</pre>
+
+<p>The script is perhaps so simple that it is not copyrightable, but
+if it is, it is licenced using GPL v2 or later at your discretion.</p>
+
+<p>After doing this, I booted a Debian CD in rescue mode in KVM with
+the new disk image attached, installed grub-pc and linux-image-686 and
+set up grub to boot from the disk image. After this, the KVM machines
+seem to work just fine.</p>
+</description>
+ </item>
+
<item>
<title>Lenny->Squeeze upgrades, apt vs aptitude with the Gnome and KDE desktop</title>
<link>http://people.skolelinux.org/pere/blog/Lenny__Squeeze_upgrades__apt_vs_aptitude_with_the_Gnome_and_KDE_desktop.html</link>
</description>
</item>
- <item>
- <title>Software updates 2010-10-24</title>
- <link>http://people.skolelinux.org/pere/blog/Software_updates_2010_10_24.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Software_updates_2010_10_24.html</guid>
- <pubDate>Sun, 24 Oct 2010 22:45:00 +0200</pubDate>
- <description>
-<p>Some updates.</p>
-
-<p>My <a href="http://pledgebank.com/gnash-avm2">gnash pledge</a> to
-raise money for the project is going well. The lower limit of 10
-signers was reached in 24 hours, and so far 13 people have signed it.
-More signers and more funding is most welcome, and I am really curious
-how far we can get before the time limit of December 24 is reached.
-:)</p>
-
-<p>On the #gnash IRC channel on irc.freenode.net, I was just tipped
-about what appear to be a great code coverage tool capable of
-generating code coverage stats without any changes to the source code.
-It is called
-<a href="http://simonkagstrom.github.com/kcov/index.html">kcov</a>,
-and can be used using <tt>kcov &lt;directory&gt; &lt;binary&gt;</tt>.
-It is missing in Debian, but the git source built just fine in Squeeze
-after I installed libelf-dev, libdwarf-dev, pkg-config and
-libglib2.0-dev. Failed to build in Lenny, but suspect that is
-solvable. I hope kcov make it into Debian soon.</p>
-
-<p>Finally found time to wrap up the release notes for <a
-href="http://lists.debian.org/debian-edu-announce/2010/10/msg00002.html">a
-new alpha release of Debian Edu</a>, and just published the second
-alpha test release of the Squeeze based Debian Edu /
-<a href="http://www.skolelinux.org/">Skolelinux</a>
-release. Give it a try if you need a complete linux solution for your
-school, including central infrastructure server, workstations, thin
-client servers and diskless workstations. A nice touch added
-yesterday is RDP support on the thin client servers, for windows
-clients to get a Linux desktop on request.</p>
-</description>
- </item>
-
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