Server virtualization

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1

I planning to virtualize all my servers once openSUSE 12.1 is released.

On my laptop I have been playing with VirtualBox on openSUSE 11.4 for a few months already. I found VirtualBox easy to install Window 7 as a VM extremely easy and nice easy feature of snapshots. I did try Xen, but had graphical and bad performance issues before I tried VirtualBox. This was of course for an typical workstation graphical environment. I very happy with VirtualBox for workstation solution, other than the annoying issue that the VM likes to pause for 20 seconds at random (guess some interrupt issue). VirtualBox makes it very nice to also copy and paste content between VMs and host.

With rapid development in the area of virtualization, I now having a very hard time in deciding which virtualization tool to use on my servers. Reading the reports that I find using Google can be very confusing, even trying to just to use the latest available reports for comparison between VirtualBox, Xen and KVM.

As these are servers, remote management will be used therefore there is really no need for GUI environment, even for Windows Server 2003 (2008 gives me headaches and is dreadfully slow on exact same bare metal hardware). As no need for GUI, there is no need for full graphics support drivers and pass through features are needed.

I be using openSUSE 12.1 to do the virualization and be the host. Though would like the host to be barebone minimalistic installation (no GUI). All Linux required services to be run in guest VMs. VirtualBox can be used headless and be setup to start up VMs on boot, with a little manual tweaking in the host.

Performance is most important for the servers, and must support openSUSE and Windows guests very well, making use of VT hardware features where possible for maximum performance.

I must be able to create snapshots of all the guests, for easy recovery of server crash (especially for Windows as it tends to become old very quickly with meta junk clogging the system). Important data will be stored in other partitions, and accessible via shares (windows) and mounts (linux). The refreshing the VM with snapshot restore will be quick and not influence the data.

I see the reports these days focus much on VirtualBox, Xen and KVM, and they will all be available on openSUSE 12.1. Most reports also seem to focus on applications that are found on workstations and worry about graphics performance, which are meaningless in a server environment. So which is best to use for server environment?

Thanx to the virtualization gurus out there for your input on the matter.

2

So I must agree that VirtualBox works pretty well under openSUSE even though some kernel developers do not like Oracle or their drivers. I have been running the latest openSUSE 12.1 in the VM with openSUSE 11.4 as the Host and I can’t tell I am even in a VM on most tasks. If you have not see this, please_try_again has a really neat script called modautocompile. You can see his article on it here:

automatically recompile kernel modules after kernel update

I even wrote a script that can be used to install his script you can find here in post number 2:

S.A.S.I. - SuSE Automated Script Installer

Basically, if you update your kernel, you need to reload the vbox drivers into the new kernel and modautocompile does that automatically for you. I have not had a chance to check it out with openSUSE 12.1 just yet but am worried since it uses the new systemd which does not use bash scripts for anything. Anyway, you must check it out and let please_try_again know how much you like his program if you decide to use it.

Thank You,

3

Thanx for you reply.

I spent the last few days really doing some long searches of the internet about these virtualization tools. In the end I settled on VirtualBox, even though KVM seems to perform slightly better according to latest test results of the last month by various individuals. Xen is a dead duck that is still floating, performance is bad, and configuration is no walk in the park either. VirtualBox has all the features I looking for, and is an absolute dream to install quests VM, with decent documentation. Also discovered the problem of sudden pauses of guest VM with 100% CPU usage. It was the ICH6 driver, using PIIX3 driver solved the problem. KVM website is a real mess. Impossible to figure out what features it has, and document is far worse than Xen. I have no idea if KVM even has the features I looking for. KVM configuration does not look very straight forward either along with installing guest VMs.

I believe KVM is going to replace Xen in the near future, but at this point of time KVM has plenty of maturing to do before it become a real contender against other solutions including VirtualBox, and be easy to configure and install guest VMs. Key to maturing is to have good documentation which it lack badly and scares off people that are new to virtualization away from the KVM solution.

Thanx for the two links I will definitely have a look at them when I start virtualization my servers on Thursday after openSUSE 12.1 is release.

4

I have a blog post on opeSUSE 12.1 and systemd. I suggest you take a look at it before you do your install as it might prove useful.

systemd and using the after.local script in openSUSE 12.1 - Blogs - openSUSE Forums

Thank You,

5

Hi sifu,

I m new in virtualbox as a server. Currently i m using vmware 2 server that have alot of problem. And i m looking for changing to vbox. but i have think that
i don’t know need help from all sifu. Host opensuse 12.1

  1. What version do i need from repo or from virtualbox website?
  2. Where can i get autostart and shutdown script?
  3. What is the easy way to backup vbox guest file? ( and can i move to other server?)

Pls help

Many Thank

6

Sorry for this late answer. Actually I have a script which makes it easy to install kvm guests. I have been using it on various Linux servers and with different libvirt versions. It is included in the vmscripts packages available on my repo (together with another script to install/run/delete virtualbox guests). VirtualBox is nice to play with, but if you’re looking for servers, I suggest kvm. the vm-create script is intended to create kvm guests from anywhere to anywhere - meaning you can install most Linux distros from the net on a remote server.

Some relevant links:

http://forums.opensuse.org/english/other-forums/development/programming-scripting/453962-vm-create-create-kvm-virtual-machines.html?highlight=vm-create
openSUSE 11.4 - vm installation guide
http://forums.opensuse.org/english/other-forums/development/programming-scripting/453961-vm-bridge-convert-virtual-machines-nat-bridge-bridge-nat.html?highlight=vm-bridge
http://forums.opensuse.org/english/get-technical-help-here/how-faq-forums/unreviewed-how-faq/465445-running-linux-live-cds-disk-less-virtual-machines-under-virtualbox.html?highlight=vm-create
http://forums.opensuse.org/english/other-forums/development/programming-scripting/465444-vboxlive-running-live-cds-vbox-disk-less-vms.html

Once you have a kvm guest, install FreeNX server on it (also in my repo), then connect to it with the NoMachine NX client from anywhere (Linux, Windows, Mac) … and Bob’s your uncle. :slight_smile:

See the funny picture posted here: http://forums.opensuse.org/english/other-forums/community-fun/surveys-polls/464645-what-about-creating-virtualization-subforum.html#post2407597

  • I haven’t tested vm-create on 12.1 hosts (even though it is in my repo :shame:) but I used it on 11.4 with libvirt versions from the virtualization repo - which are more cutting edge, as well as on Fedora and ArchLinux. I would assume that it works.
7

The Oracle version has a little bit more features. Have a look at this post on an easy method to install it:
http://forums.opensuse.org/english/get-technical-help-here/how-faq-forums/unreviewed-how-faq/465445-running-linux-live-cds-disk-less-virtual-machines-under-virtualbox.html#post2407566

It does actually install virtualbox automatically when you start the first guest (from an iso image downloaded from the Internet). To only install and properly configure VirtualBox without running a guest, just type:

vboxlive --install

You need to install the vmscripts package first, as described is the link.

8

I’ve been using xen for company servers for about 2 years. I’m running 4 linux virtual machines and 4 win7 machines. Last week I’ve update to 12.1 and the update broke down xen, so it can’t start any vm. So I converted all my machines to virtual box (had to reinstall windows unfortunately) and I have to say that performance went down dramatically. So I’m just waiting impatiently for xen to be fixed, so I can go back.

9

Sorry for repeating myself but … a virtualization subforum would help sort these kinds of problems.

10

What I wanted to say is that virtualbox is great for desktop virtualization. Run one or two vms and see their outputs. And is bad when running many vms headless. Xen is completely oposite. It’s great for running many vms headless for ssh, rdesktop usage and is completely useless for desktop virtualization, because it’s graphical output and mouse emulation is really bad.
So for your usage is xen much better choice.

11

I think Xen was yesterday. Give a try to kvm. It doesn’t require a specific kernel and it is simpler in many ways. If you have some time - and you’re still using Xen, try to install FreeNX in your Xen guests and connect to them with a NX client. I can not see the difference between kvm (I’m not using Xen) and VirtualBox while using FreeNX inside kvm. But I’m not after 3D games either. Well … if you look closer, you can see the difference, but FreeNX on kvm is acceptable as desktop too and of course much better than VirtualBox as server.

12

I’ll try it, it looks good.

13

So I’ve installed KVM and converted my xen virtual machines into it and performance is better than it was in vbox, but still much worse than it was in xen. It’s enough to run zypper update on 3 linux machines and everthing else (even host) is so slow that it’s almost unusable. In xen I wouldn’t even notice any performance drop.

14

Keep in mind that Xen can use paravirtualization while kvm can not. So the performance in kvm might be depending on the host CPU more than it would in Xen … I guess. So if you have a slow processor and many virtual machines, Xen should still be a lot faster. (Tell me if I’m wrong).

15

I’ve updated all my vms to use virtio disks and ethernet (bit painfull process at first) and it seems that performance got bit better. I’m not sure if it’s on par with xen, but it’s useable.

16

Definitely! You should use the virtio driver. Otherwise disk I/O is not fun. It’s definitely usable. Notice that vm-create was written to handle both kvm an Xen machines - because libvirt, virsh and virt-manager can do both - but i never tested it under Xen, as I don’t use it.

17

It seems that with virtio disks windows shows blue screen very often and data on disk are getting damaged. It seems to happen more often since I switched from raw file to LVM logical disk. :frowning:

18

We have a new forum for VM questions that you can find here and its brand new:

Virtualization

Please use it to post any new questions on Virtualizations.

Thank You,