I should have a server-class AMD Opteron system ready to use soon; it is
still being built. I want to install Fedora 16 on this as a
virtualization host. How do I get started with that? Do I need to
install an Xen kernel from M. A. Young? I want to have as much "Dom0"
functionality as possible. I know from posing an earlier question that
Xen has limitations with USB support. My friend will be using a Windows
7 guest instance and is heavily dependent on USB devices.
Thanks for any advice!
libreoffice on F16 requires yajl 1.0, but virt-preview built libvirt
against yajl 2.0. This means that it is not possible to use
virt-preview on an F16 machine with libreoffice installed:
--> Finished Dependency Resolution
Error: Package: raptor2-2.0.4-2.fc16.x86_64 (@anaconda-0)
Removing: yajl-1.0.12-1.fc16.x86_64 (@anaconda-0)
Updated By: yajl-2.0.1-1.fc16.x86_64 (fedora-virt-preview)
It looks like we need to back out the yajl changes from virt-preview,
and rebuild libvirt to not require the newer yajl libraries.
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org
I've got VMware Server 2.0.2 running on a CentOS 5 system (other things
are running on the CentOS besides the VMware). I've got a new system and
want to migrate off of the VMware, but to what? My new machine is
currently running Fedora 14, but could be made to run any Red Hat style
Is there a 'How To' out there that tells about this 'migration' (tried
What about a KVM tutorial?
Can I use the existing VMware Server VM definitions on another machine?
Under F15, I had this in my crontab and it worked fine:
@reboot sleep 30; /usr/bin/qemu-kvm -hda
/var/lib/libvirt/images/MikeWindows.img -usbdevice tablet -m 2048 -k
en-us -vga qxl -spice port=5930,disable-ticketing &
After upgrading to F16, I find that:
1) "-usbdevice tablet" doesn't work. I have to delete that clause to get
any sort of mouse movement. I saw something saying the tablet mode was
deprecated, but it should still work...
2) Networking (the "user mode" stack) isn't working at all. My Windows
XP client sees the NIC, but no connection is established.
Has anyone else struggled with this?
You might want to change the default virtio disk cache mode.
I was just doing some tests (after finally getting the latest
virtio scsi drivers installed correctly on my Windows XP virtual
The test was running the little "sdelete" tool which writes
a temp file full of zeroes to the disk in order to zero
out all the free space (very handy for converting the resulting
image to a maximally compressed qcow2 image).
It had just taken about 8 hours to do this on 20GB qcow2
image that has about 14GB unused and that seemed excessive,
so I thought I'd try different cache modes with updated
virtio drivers. My test was starting the sdelete run inside
the virtual machine and starting this on the host:
sleep 600 ; virsh destroy winxppro
That gives sdelete 10 minutes to grow the image file, then
I could ls -l the file to see how big it grew. With
the cache=default (which is apparently writethrough)
setting I get:
-rw-r--r-- 1 root root 423296512 Nov 13 16:27 winxppro.img
With cache=none I get:
-rw-r--r-- 1 root root 12813860864 Nov 13 16:44 winxppro.img
With cache=writeback I get:
-rw-r--r-- 1 root root 14574551040 Nov 13 16:58 winxppro.img
(which actually completed the whole sdelete zero fill process
in less than 10 minutes).
Needless to say, I have switched my KVM settings to writeback :-).
Default time to fill disk: 8 hours.
Writeback time to fill disk: less than 10 minutes.
That seems like just a bit of disparity. Since I was
using qcow2, I never expected really high performance, so
I didn't try different settings till now - I wish I had
tried it earlier :-).
I saw a thread a month or so ago on disk performance, and
just for grins, I thought I'd try different disk cache settings
for my Windows XP virtual machine that has a qcow2 image
file (I know qcow2 is never going to be really fast, but I
thought I'd see if I could get any improvement at all).
Every cache mode I tried (changing them in the advanced
options of the hardware viewer screen in virt-manager) resulted
in the XP machine getting into a bluescreen loop when I booted
Finally set it back to "default" and the XP machine stopped
Are other cache modes supposed to work OK? Should I
report a bug on some component? Should I try and capture
the bluescreen content? (It flickers in and out really fast).
The main reason I was trying this is because it sure seems
like the qcow2 image gets slower and slower every time I
upgrade fedora and get new and improved qemu and libvirt
code. I don't have solid benchmarks, but it sure feels
slower. Has optimization of cases that are supposed to be fast
slowed down qcow2 somehow?
I'm currently trying to build an updated base image by
doing the trick of writing a giant file of zeros to fill
up the disk so I can then convert the mostly zero image to
a new qcow2 file, and the rate it is going makes it seem like
it may well be tomorrow before it finishes writing the
10 GB or so of zeros it needs to finish filling up the
None of my CPUs are showing over 1% utilization and gkrellm
is showing only 2.0M disk write rate, so it sure seems like
all the components involved are spending more time just
waiting than anything else.
I just submitted this bug:
Apparently Windows XP thinks the video hardware has changed
on fedora 16 host (I was using qxl and spice on fedora 15 host).
If this is expected rather than a bug, which drivers do I
install to made XP happy when hosted on fedora 16?
The Windows XP machine on fedora 15 currently has the
Red Hat QXL GPU version 184.108.40.206 (9/29/2010) video
I'm going to test nested virtualization on Intel with F16 host.
I have used it successfully with Amd, where it is enabled by default
in its kvm-amd module.
F16 having now
[root@f16 ~]# uname -r
and the same confirmations in its kernel-doc
# uname -r
# modinfo kvm-intel
In F16 indeed we have now:
# modinfo kvm-intel
Based on docs, the "nested" option is disabled by default on Intel
(and probably not changed in Fedora?)
Did anyone already enable it and test nested virtualization
functionalities on Intel during F16 Beta/RC cycle and has now results
thanks in advance,
Here's one for the calendar - a 2 day track at FOSDEM devoted to Open
Source Virtualization and Cloud.
Hope to see you there! :)
-------- Forwarded Message --------
> From: Thierry Carrez <thierry(a)openstack.org>
> To: openstack(a)lists.launchpad.net <openstack(a)lists.launchpad.net>
> Subject: [Openstack] OpenStack at FOSDEM
> Date: Fri, 11 Nov 2011 11:34:22 +0100
> Hi everyone,
> Our OpenStack devroom was accepted for FOSDEM, February 4-5, 2012 in
> Brussels. It was actually grouped with other "Open Source virtualization
> and cloud" projects in a giant devroom (550-seat auditorium) that lasts
> the full 2 days !
> Expect a CFP in the coming weeks...
> See other devrooms at:
> Thierry Carrez (ttx)
> Release Manager, OpenStack
> Mailing list: https://launchpad.net/~openstack
> Post to : openstack(a)lists.launchpad.net
> Unsubscribe : https://launchpad.net/~openstack
> More help : https://help.launchpad.net/ListHelp
I have lots of memory for the virtual machines I run.
Any work at all that KSM does will be a waste of time,
but on fedora 16 there does not appear to be a KSM
service I can disable with either chkconfig or the
systemd tools, yet ksmd is running.
How the heck do I disable it? (Or is that a lost cause,
and I might as well just go ahead and let it run :-).