xen kvm ubuntu experienced opinions wanted

syx · 25th June 2009, 11:01 AM

Hi,

I just looked at elvis's fat thread about linux and have been following threads about virtual machine stuff here loosely.

In the fat thread he suggests xen but people have been talking about kvm a fair bit.

I am a free user of vmware at the moment and have been eyeballing the pay for features for vmware for next year. However you guys keep talking up how xen does it for free.

Ubuntu is my favoured distro for all the usual reasons.

I downloaded xen 5.0 but dont have a machine spare that I can play with it on yet. (i only have workstations free and it has hardware requirements like vmware, or is that just wrong ?)

If I install ubuntu on a workstation and install xen on that (using the howto link I found in the fat thread thanks!) is that good practice for a possible migration to the proper baremetal install for my real servers ?
Are all the commands and things the same for the desktop xen and 'proper' xen ?

Is xen still the best ? kvm ?

Any other 'gotchas' that you can suggest ?

Thanks

cleary · 25th June 2009, 11:15 AM

RedHat were one of the big backers for Xen, however in the last 12 months they have bought a company called Qumranet which owned KVM. Surprise surprise their virtualisation focus has now shifted to KVM.

My work is a predominantly redhat shop for servers, therefore we've begun using kvm for our server virtualisation. Combine it with libvirt management tools and you get migration capabilities, GUI controller tools for multiple hosts/domains, a virt-shell for cli control and various other bits and pieces.

I like kvm, and it's where I see the future of virtualisation on linux.

I'm no expert on Xen, but I understand there are limitations on guest software, kernel versions, etc.

elvis · 25th June 2009, 11:47 AM

Xen are making leaps and bounds in their ability to virtualise and present real hardware back to specific VMs (or all VMs), and are still the kings of virtualised I/O speeds (VMWare are at times an entire order of magnitude slower, despite what their marketdroids insist).

The glaring downside is that they are frequently many kernel releases behind. That means if you want bleeding edge kernel support for whatever reason (be it features, performance, hardware support, or whatever) then you're stuffed.

This is where KVM shines through. I think KVM is looking good because it can catch up with Xen in terms of I/O performance and device virtualisation features, and is always guaranteed to be the latest kernel. And as Cleary said, given RedHat's input into the project (both in terms of human beings and dollars), KVM is only headed in one direction: up.

Quote:

Originally Posted by cleary

My work is a predominantly redhat shop for servers, therefore we've begun using kvm for our server virtualisation.

What do you use as your base host OS?

I was under the impression that all current RHEL5 stuff (including the latest 5.3) was still Xen-based, and that KVM was being introduced to Fedora and eventually RHEL6. Is that correct?

cleary · 25th June 2009, 12:00 PM

Quote:

Originally Posted by elvis

...What do you use as your base host OS?

I was under the impression that all current RHEL5 stuff (including the latest 5.3) was still Xen-based, and that KVM was being introduced to Fedora and eventually RHEL6. Is that correct?

I'm not involved with the project directly - however at least one host is CentOS 5.3. It does come with pre-packaged kvm, however we are running a much newer version. It's still in trial mode though, we have not yet virtualised critical services.

syx · 25th June 2009, 3:56 PM

I thought i'd be spending the day creating virtual machines in cool new(to me) virtual machine software.

Instead ive spent the day following guides that dont work for kvm,virtualbox,xen
Couldnt even install them.

Dissapointing to see that ubuntu still cant get the damn proxy settings universal so dumb, and then you can put the proxy settings in synaptic but that doesnt work for command line apt.
Apt is great, when it works...why cant there be a prompt for your user

ass when it detects error 407 authentication failed !!

Maybe its my fault, I only had a normal 'desktop' version of ubuntu 9.04 as opposed to the server version.

Ive been using apt-get install to get the packages for the different programs.

btw this page has the command line to create a vm in kvm

Code:

vmbuilder kvm ubuntu --suite=intrepid --flavour=virtual --arch=amd64 --mirror=http://192.168.0.100:9999/ubuntu -o --libvirt=qemu:///system --tmpfs=- --ip=192.168.0.101 --part=vmbuilder.partition --templates=mytemplates --user=administrator --name=Administrator --pass=howtoforge --addpkg=vim-nox --addpkg=unattended-upgrades --addpkg=acpid --firstboot=boot.sh --mem=256 --hostname=vm1 --bridge=br0

Holy crap, how can you say you prefer a command line a mile long with a straight face !

memnoch · 25th June 2009, 11:45 PM

Command line commands can be built into scripts, gui pointy clicky shit isn't so hot to automate..
Also didnt ubuntu pull out support for dom0 xen support in the latest versions.
If you want xen and apt-get check out lenny.
Or if you prefer rpm, look at CentOS and the custom Xen repo these guys have. http://www.gitco.de/repo/

Im running 5 esx servers with about 60 VMs total. And another lot of Xen boxes with more VMs (30ish and growing by 2-5 weekly) on them. A mix of Windows and Linux on both.

VMware performance does not stack up to Xen (in HVM or Paravirt..).

Add on the fact you need to ensure you have vmware tools installed, and are stuck managing it through a clunky gui, it does not make sense to be picking vmware when Xen does it better for free.

We initially went with ESX because it would be quick to get up and running (which it was), however now we have time to develop the infrastructure more, Xen is choice #1.

KVM is still lagging a little bit in terms of HVM performance from our testing. Im hoping redhat have that sorted by RHEL6.

And to top it off we recently had a vmware virtual switch stop passing all traffic and the associated NICs not work until the ESX box was rebooted...

My advise try out Xen and KVM, see which one you are happy with. And test all the administration tools. If you are gui kinda person check out http://www.convirture.com/

GumbyNoTalent · 26th June 2009, 10:45 AM

Quote:

Originally Posted by syx

Instead ive spent the day following guides that dont work for kvm,virtualbox,xen
Couldnt even install them.

Here is a Ubuntu 9.04 Desktop Virtualbox install guide...

Menu
System>Administration>Synaptic Package Manager

Enter you passwaord when asked.

Search for VirtualBox.

Check virtualbox-ose make sure that these other packages are selected as dependencies (they should);
vboxgtk
virtualbox-ose-guest-utils

Now press Apply the big green tick.

Wait... and now VirtualBox is installed, go to Sun and read up on the guides on how to use.

Hope that helps you, also works with 8.04 LTS Desktop.

---------------------------------------------------------------

Xen
http://howtoforge.com/ubuntu-8.04-se...u-repositories

I haven't tried this, but I use HowToForge all the time so Im confident.

GumbyNoTalent · 26th June 2009, 10:50 AM

Quote:

Originally Posted by memnoch

My advise try out Xen and KVM, see which one you are happy with. And test all the administration tools. If you are gui kinda person check out http://www.convirture.com/

Here are some technologies I have been keeping an eye on...

http://ovirt.org/
http://virt-manager.et.redhat.com/
http://virt-factory.et.redhat.com/
http://et.redhat.com/~rjones/virt-p2v/

syx · 26th June 2009, 12:44 PM

Thanks for the replies, its a steep learning curve as usual.

I tried the server version of ubuntu 8.10 to see if that would work better than the 9.04 normal version but it had a error with a usb device 2 sr20 or something, and it wouldnt boot. should have written it down, idiot..

Anyway im downloading the server version of ubuntu 9.04 to try later.

Ive put xenserver 5.0 on a optiplex 755 to play with. This is more familier, same kind of setup as esxi and a gui client to control it with.

Now to work out how to upload an iso to the xenserver to use to install some OS's

fornar · 26th June 2009, 2:39 PM

Hi

I work with cleary and have done one implmentation of KVM on centos 5.3.
The version of kvm that came with 5.3 was unable to successfuly run MS server 2008. It was like version 35. Hence we got the latest kvm at the time which i think was version 74. I believe it is now up to version 85

We followed the below howto

http://wiki.centos.org/HowTos/KVM

We are successfully running Server 2008 in a VM now.

25th June 2009, 11:15 AM	#2
cleary Mental in the Face Join Date: Apr 2003 Location: Griffith NSW Posts: 3,924	RedHat were one of the big backers for Xen, however in the last 12 months they have bought a company called Qumranet which owned KVM. Surprise surprise their virtualisation focus has now shifted to KVM. My work is a predominantly redhat shop for servers, therefore we've begun using kvm for our server virtualisation. Combine it with libvirt management tools and you get migration capabilities, GUI controller tools for multiple hosts/domains, a virt-shell for cli control and various other bits and pieces. I like kvm, and it's where I see the future of virtualisation on linux. I'm no expert on Xen, but I understand there are limitations on guest software, kernel versions, etc. __________________ SmugMug

25th June 2009, 3:56 PM	#5
syx Member Join Date: Jul 2001 Location: Mount Gambier Posts: 416	I thought i'd be spending the day creating virtual machines in cool new(to me) virtual machine software. Instead ive spent the day following guides that dont work for kvm,virtualbox,xen Couldnt even install them. Dissapointing to see that ubuntu still cant get the damn proxy settings universal so dumb, and then you can put the proxy settings in synaptic but that doesnt work for command line apt. Apt is great, when it works...why cant there be a prompt for your userass when it detects error 407 authentication failed !! Maybe its my fault, I only had a normal 'desktop' version of ubuntu 9.04 as opposed to the server version. Ive been using apt-get install to get the packages for the different programs. btw this page has the command line to create a vm in kvm Code: vmbuilder kvm ubuntu --suite=intrepid --flavour=virtual --arch=amd64 --mirror=http://192.168.0.100:9999/ubuntu -o --libvirt=qemu:///system --tmpfs=- --ip=192.168.0.101 --part=vmbuilder.partition --templates=mytemplates --user=administrator --name=Administrator --pass=howtoforge --addpkg=vim-nox --addpkg=unattended-upgrades --addpkg=acpid --firstboot=boot.sh --mem=256 --hostname=vm1 --bridge=br0 Holy crap, how can you say you prefer a command line a mile long with a straight face ! __________________ "In the Morning !"

25th June 2009, 11:45 PM	#6
memnoch Member Join Date: Jan 2002 Location: San Francisco, California Posts: 508	Command line commands can be built into scripts, gui pointy clicky shit isn't so hot to automate.. Also didnt ubuntu pull out support for dom0 xen support in the latest versions. If you want xen and apt-get check out lenny. Or if you prefer rpm, look at CentOS and the custom Xen repo these guys have. http://www.gitco.de/repo/ Im running 5 esx servers with about 60 VMs total. And another lot of Xen boxes with more VMs (30ish and growing by 2-5 weekly) on them. A mix of Windows and Linux on both. VMware performance does not stack up to Xen (in HVM or Paravirt..). Add on the fact you need to ensure you have vmware tools installed, and are stuck managing it through a clunky gui, it does not make sense to be picking vmware when Xen does it better for free. We initially went with ESX because it would be quick to get up and running (which it was), however now we have time to develop the infrastructure more, Xen is choice #1. KVM is still lagging a little bit in terms of HVM performance from our testing. Im hoping redhat have that sorted by RHEL6. And to top it off we recently had a vmware virtual switch stop passing all traffic and the associated NICs not work until the ESX box was rebooted... My advise try out Xen and KVM, see which one you are happy with. And test all the administration tools. If you are gui kinda person check out http://www.convirture.com/ Last edited by memnoch; 25th June 2009 at 11:48 PM. Reason: more infos

26th June 2009, 12:44 PM	#9
syx Member Join Date: Jul 2001 Location: Mount Gambier Posts: 416	Thanks for the replies, its a steep learning curve as usual. I tried the server version of ubuntu 8.10 to see if that would work better than the 9.04 normal version but it had a error with a usb device 2 sr20 or something, and it wouldnt boot. should have written it down, idiot.. Anyway im downloading the server version of ubuntu 9.04 to try later. Ive put xenserver 5.0 on a optiplex 755 to play with. This is more familier, same kind of setup as esxi and a gui client to control it with. Now to work out how to upload an iso to the xenserver to use to install some OS's __________________ "In the Morning !"

25th June 2009, 11:01 AM	#1
syx Member Join Date: Jul 2001 Location: Mount Gambier Posts: 416	xen kvm ubuntu experienced opinions wanted Hi, I just looked at elvis's fat thread about linux and have been following threads about virtual machine stuff here loosely. In the fat thread he suggests xen but people have been talking about kvm a fair bit. I am a free user of vmware at the moment and have been eyeballing the pay for features for vmware for next year. However you guys keep talking up how xen does it for free. Ubuntu is my favoured distro for all the usual reasons. I downloaded xen 5.0 but dont have a machine spare that I can play with it on yet. (i only have workstations free and it has hardware requirements like vmware, or is that just wrong ?) If I install ubuntu on a workstation and install xen on that (using the howto link I found in the fat thread thanks!) is that good practice for a possible migration to the proper baremetal install for my real servers ? Are all the commands and things the same for the desktop xen and 'proper' xen ? Is xen still the best ? kvm ? Any other 'gotchas' that you can suggest ? Thanks __________________ "In the Morning !"

26th June 2009, 2:39 PM	#10
fornar Member Join Date: May 2002 Location: Beelbangera Posts: 53	Hi I work with cleary and have done one implmentation of KVM on centos 5.3. The version of kvm that came with 5.3 was unable to successfuly run MS server 2008. It was like version 35. Hence we got the latest kvm at the time which i think was version 74. I believe it is now up to version 85 We followed the below howto http://wiki.centos.org/HowTos/KVM We are successfully running Server 2008 in a VM now.