Somewhere out there! » Kvm http://stateless.geek.nz Sat, 04 Feb 2012 09:00:43 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 Bookmarks for February 3rd through February 4th http://stateless.geek.nz/2012/02/04/bookmarks-for-february-3rd-through-february-4th/ http://stateless.geek.nz/2012/02/04/bookmarks-for-february-3rd-through-february-4th/#comments Sat, 04 Feb 2012 09:00:43 +0000 Nicholas Lee http://stateless.geek.nz/?p=950 These are my links for February 3rd through February 4th:

]]> http://stateless.geek.nz/2012/02/04/bookmarks-for-february-3rd-through-february-4th/feed/ 0 Bookmarks for January 9th through January 11th http://stateless.geek.nz/2012/01/11/bookmarks-for-january-9th-through-january-11th/ http://stateless.geek.nz/2012/01/11/bookmarks-for-january-9th-through-january-11th/#comments Tue, 10 Jan 2012 13:00:14 +0000 Nicholas Lee http://stateless.geek.nz/?p=909 These are my links for January 9th through January 11th:

]]> http://stateless.geek.nz/2012/01/11/bookmarks-for-january-9th-through-january-11th/feed/ 0 Bookmarks for December 13th through December 14th http://stateless.geek.nz/2011/12/15/bookmarks-for-december-13th-through-december-14th/ http://stateless.geek.nz/2011/12/15/bookmarks-for-december-13th-through-december-14th/#comments Wed, 14 Dec 2011 12:00:00 +0000 Nicholas Lee http://stateless.geek.nz/2011/12/15/bookmarks-for-december-13th-through-december-14th/ These are my links for December 13th through December 14th:

]]> http://stateless.geek.nz/2011/12/15/bookmarks-for-december-13th-through-december-14th/feed/ 0 Bookmarks for June 20th through December 13th http://stateless.geek.nz/2011/12/13/bookmarks-for-june-20th-through-december-13th/ http://stateless.geek.nz/2011/12/13/bookmarks-for-june-20th-through-december-13th/#comments Tue, 13 Dec 2011 01:27:31 +0000 Nicholas Lee http://stateless.geek.nz/?p=848 These are my links for June 20th through December 13th:

]]> http://stateless.geek.nz/2011/12/13/bookmarks-for-june-20th-through-december-13th/feed/ 0 Lucid libvirt http://stateless.geek.nz/2011/12/13/lucid-libvirt/ http://stateless.geek.nz/2011/12/13/lucid-libvirt/#comments Tue, 13 Dec 2011 01:23:07 +0000 Nicholas Lee http://stateless.geek.nz/?p=873 Lucid does not seem to work well with libvirt/kvm, there are several bugs that seem to be fixed in Maverick but not in Lucid.

From syslog:

error : qemuSetupCgroup:1955 : Unable to create cgroup for DOMAIN: No such file or directory
error : qemuRemoveCgroup:2045 : internal error Unable to find cgroup for DOMAIN#012

Re: [libvirt] FYI, “Unable to create cgroup for …”

This is a bug in systemd. It periodically scans all mounted cgroups
and deletes any directories which don’t contain any attached processes.
Needless to say this breaks libvirt, and possibly other apps, which
don’t expect 3rd parties to be deleting their directories.

https://bugzilla.redhat.com/show_bug.cgi?id=678555

Best solution for this that I’ve found on lucid is: Bug 696218 – Unable to create cgroup: No such file or directory

I was able to solve it by modifying the configuration in the file
/etc/libvirt/qemu.conf: 

 cgroup_controllers = [ ]

setgid, setuid needed by /etc/apparmor.d/abstractions/libvirt-qemu

=== modified file 'apparmor.d/abstractions/libvirt-qemu'
--- apparmor.d/abstractions/libvirt-qemu 2010-04-30 15:33:20 +0000
+++ apparmor.d/abstractions/libvirt-qemu 2010-05-12 17:26:56 +0000
@@ -8,6 +8,8 @@
   capability dac_override,
   capability dac_read_search,
   capability chown,
+ capability setgid,
+ capability setuid,

Libvirt/kvm permissions/ownership issue on upgrade from Karmic to Lucid and error: operation failed: failed to retrieve chardev info in qemu with ‘indev’

libvirtError: internal error unable to start guest: libvir: QEMU
error : cannot set ownership

or 

 error: operation failed: failed to retrieve chardev info in qemu with 'indev'

Add the following to /etc/libvirt/qemu.conf:

# The user ID for QEMU processes run by the system instance
#user = "libvirt-qemu"
user = "root"

# The group ID for QEMU processes run by the system instance
group = "kvm"

map serial port throws “chardev: opening backend “tty” failed”

There seems to be a problem with the apparmor profile of libvirt (see bug #54579). After adding the line to /etc/apparmor.d/abstractions/libvirt-qemu and reloading the profile it worked for me.

/dev/ttyS* rw,

Few other links:

]]> http://stateless.geek.nz/2011/12/13/lucid-libvirt/feed/ 0 Random MAC address for libvirt http://stateless.geek.nz/2011/12/08/random-mac-address-for-libvirt/ http://stateless.geek.nz/2011/12/08/random-mac-address-for-libvirt/#comments Thu, 08 Dec 2011 00:25:16 +0000 Nicholas Lee http://stateless.geek.nz/?p=857 Snippet for generating a random MAC address. Useful if adding interfaces to a libvirt xml define file.

MACADDR="52:54:$(dd if=/dev/urandom count=1 2>/dev/null | md5sum | sed 's/^\(..\)\(..\)\(..\)\(..\).*$/\1:\2:\3:\4/')";
echo $MACADDR
echo "
<interface type='bridge'>
<mac address='$MACADDR'/>
<source bridge='br233'/>
<model type='virtio'/>
</interface>
"
]]> http://stateless.geek.nz/2011/12/08/random-mac-address-for-libvirt/feed/ 1 Bookmarks for April 15th through April 20th http://stateless.geek.nz/2011/04/20/bookmarks-for-april-15th-through-april-20th/ http://stateless.geek.nz/2011/04/20/bookmarks-for-april-15th-through-april-20th/#comments Wed, 20 Apr 2011 01:00:33 +0000 Nicholas Lee http://stateless.geek.nz/?p=791 These are my links for April 15th through April 20th:

]]> http://stateless.geek.nz/2011/04/20/bookmarks-for-april-15th-through-april-20th/feed/ 0 Bookmarks for April 3rd through April 11th http://stateless.geek.nz/2011/04/11/bookmarks-for-april-3rd-through-april-11th/ http://stateless.geek.nz/2011/04/11/bookmarks-for-april-3rd-through-april-11th/#comments Sun, 10 Apr 2011 22:01:09 +0000 Nicholas Lee http://stateless.geek.nz/?p=769 These are my links for April 3rd through April 11th:

]]> http://stateless.geek.nz/2011/04/11/bookmarks-for-april-3rd-through-april-11th/feed/ 0 Bookmarks for March 4th through March 7th http://stateless.geek.nz/2011/03/07/bookmarks-for-march-4th-through-march-7th/ http://stateless.geek.nz/2011/03/07/bookmarks-for-march-4th-through-march-7th/#comments Sun, 06 Mar 2011 21:00:40 +0000 Nicholas Lee http://stateless.geek.nz/?p=738 These are my links for March 4th through March 7th:

]]> http://stateless.geek.nz/2011/03/07/bookmarks-for-march-4th-through-march-7th/feed/ 0 kvm vs qemu-kvm vs kvm-kmod http://stateless.geek.nz/2009/10/16/kvm-vs-qemu-kvm-vs-kvm-kmod/ http://stateless.geek.nz/2009/10/16/kvm-vs-qemu-kvm-vs-kvm-kmod/#comments Thu, 15 Oct 2009 21:01:10 +0000 Nicholas Lee http://stateless.geek.nz/?p=710 Ubuntu recently change their package names for kvm.  This comment posted on qemu-0.11.0 Released provides an explanation:

qemu-kvm includes features and fixes from upstream qemu and so takes its naming scheme from upstream qemu. You can think of it as qemu optimized for kvm. Note too that qemu-kvm does not include the kernel module but only the userspace and considered to be stable.

kvm-xx on the other hand is the development branch of kvm and not considered to be stable. It’s naming scheme is arbitrary and it also takes features from upstream qemu.

…

kvm-kmod is different to kvm-xx. You can think of kvm-kmod as a subset of the kvm-xx. KVM-xx = userspace + kernel where kvm-kmod is the kernel part of it and qemu-kvm is the userspace part (the guest process itself). You can apply the kvm-kmod to any distro version or linux version.. it’s just the kernel driver. However, without the userspace part, you can’t do much with it.

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