My openSUSE 12 Journal - 4: Minor Frustrations

This is my fourth journal entry for openSUSE 12.1 and it has been two weeks of operational use on both my Thinkpad and home PC.  Here are some additional minor frustrations and some workarounds... and yes, I have posted on the openSUSE forums (just in case you'd ask).

Boot 12.1 using the old System V init
In my first journal entry, I complained the lack of "chattiness" during boot since the adoption of Systemd.  You can easily switch to the old System V init on boot.  At the grub boot loader screen (usual 8 seconds delay) and before you hit Enter to boot, press the F5 button to switch from default to System V.  Now, press Enter to boot and press the Esc key during the splash screen to see the familiar System V init messages.

[Update on 6 Dec 2011]: Tired of pressing F5 every time on boot? Append the following to the end of the line:
init=/sbin/sysvinit
For example, in /boot/grub/menu.lst, at the end of the line starting with "kernel /boot/vmlinuz-3.1.0-1.2-desktop...", append the line above and save the file.  On the next boot, you can verify the change in the Boot Options field.  Press Enter and you will boot up 12.1 under the old System V init.

Getting Started with KVM on SLES 11 SP1

This blog post is long overdued and I apologized to those who had encouraged me to do so earlier and I procrastinated.

With SLES 11 SP1, officially available earlier in June 2010, KVM (Kernel-based Virtual Machine) is officially supported in addition to the more mature Xen virtualization (since 2006). You can install both hypervisors on the same installation of SLES 11 SP1 but you can only choose to use one or the other and not both at the same time (reboot required to switch).

Pre-requisites:

This is an important and usually overlooked step, I'm guilty of this... twice (Ouch!), but KVM requires x86 CPUs that supports hardware level virtualization. For Intel chips, the Intel-VT feature and for AMD chips, the equivalent AMD-V feature must be available.

Question: How do I know my CPU supports hardware level virtualization?
Answer 1: If you have your CPU model number, you can google or just visit the support pages at Intel or AMD.
Answer 2: If you already have SLES 11 SP1 installed, execute this command as root via the Terminal: cat /proc/cpuinfo and your CPU Model name will show up.

More importantly, this feature must be turned ON. I've noticed that they (Intel-VT and AMD-V) are usually disabled by default. To turn them on, you'll need to go into the BIOS and, under some CPU configuration, toggle it ON.

Question: How do I know if Intel-VT or AMD-V is available with SLES 11 SP1 already booted up?
Answer: Execute egrep "vmx|svm" /proc/cpuinfo and if this command returns empty, you're out of luck. For Intel-VT, vmx is present under the CPU flag. For AMD-V, svm is present.

The consequence of not checking, while not catastrophic, does cause disappointments especially when that particular CPU does not support this feature and you'll have to find other means to virtualize. On such a machine and if you're only virtualizing SLES 10 or 11, you can install Xen and it will work since Xen supports para-virtualization. However, if you intend to virtualize other Linux and Windows, you'll need to look at VMWare (eg VMWare Server coz its free) and/or any other hypervisor that provides full hardware emulation for virtualization.

Installation:

SLES 11 SP1 does not install Xen or KVM by default (if you keep clicking Next and do not modify the Software Selection during installation). Fortunately, SUSE Engineering made it real easy to install either Xen or KVM (or both) via YaST.

In YaST, under the Virtualization section, click on Install Hypervisor and Tools. You will be presented with a simple dialog with 2 checkboxes. You may checked both boxes to install both Xen and KVM or just the checkbox for KVM.



Click Accept and YaST will take care of installing all the required packages (including management tools) for KVM and/or Xen.

Its important that you know that, virt-manager, the GUI to manage virtual machines and configurations can be used to administer both Xen and KVM in SLES 11 SP1. This is a great feature because users who are already familiar with Xen on SLES can start using KVM quickly. Another great example of engineering thought put into releasing a quality Linux distribution for the enterprise.

Once installation is complete, you are ready to use KVM (without rebooting). Just to be sure that KVM is ready for action, you can execute (as root) lsmod | grep kvm and see if the kvm module has been loaded. You can find the KVM release notes/support statements under the /usr/share/doc/packages/kvm directory.

Using KVM for the first time:

Bring up the Virtual Machine Manager (aka virt-manager) either via YaST -> Virtualization -> Virtual Machine Manager OR the command (as root) virt-manager.



For the Virtual Machine Manager (VMM) GUI screenshot above, you should have an empty list of virtual machines under localhost(QEMU) since you're using KVM for the first time.

At this point, before you create your first virtual machine, I would advise you define the virtual network settings. By default, there is a "default" virtual network (it may not be activated however) that is configured to NAT (Network Address Translation). This means that your virtual machine will pick up, via DHCP, an IP address that is local to your machine but capable of accessing the Internet via your host network card (or WiFi). If this setting works for you, great. Otherwise, you have the option of creating other virtual network (host-only or bridged) via the VMM GUI.

To administer these virtual networks, double-click on localhost (QEMU) in the VMM. Alternatively, you can click on Edit -> Host Details on the VMM menubar. Click on the Virtual Networks Tab when another window appears. I won't bother going into details here because the GUI is rather straight-forward. Only thing that is worth pointing out is NOT to forget clicking on the "play" button to start your virtual network.



Good, you are all set to create your first virtual machine with KVM. If you are familiar with the virtual machine creation wizard for Xen since SLES 10 SP2, it will be plain sailing for you since SLES re-use the same GUI interfaces. For those who are not familiar, well, its really not that tough clicking Next, modifying preferences and clicking Finish to create a virtual machine and start it up.

Finally, for the more hardcore users reading this blog, here are the directories that will be of interests to you:

VM disk images - /var/lib/kvm/images/
VM meta-data - /etc/kvm/vm/
Logs - /var/log/kvm/ and /var/log/libvirt/
Configurations - /etc/libvirt/ and /etc/libvirt/qemu/networks/

Enjoy!

KVM in SUSE Linux Enterprise Server 11 SP 1

At Novell BrainShare Amsterdam last week, the Geekos were handing out SUSE Linux Enterprise Server 11 SP1 (RC4) at IT Central. So off came my DVD drive and I installed it on a separate partition on my Thinkpad.

Since its a Release Candidate (RC4) and not the final GA version due on 2nd June, I wanted to have a quick look at how KVM works since its an officially supported hypervisor in SP1 (other than the very established Xen shipped and supported since SLES 10 back in 2006).

I've been using Xen and helping partners & customers implement it for a few years, without any knowledge of KVM, I wanted to dive right in and see how far I'd go. I am very impressed with the engineering and thought put into how KVM is packaged with SLES 11 SP1. This is truly a fine example of an "Enterprise" grade product. I was able to virtualize an instance of SLES 11 SP1 and MS Windows 7 with no assistance. The KEY is the tools (libvirt & virt-manager) for Xen, which I'm familiar since SLES 10, is now capable of managing both Xen and KVM in SLES 11 SP1. Depending if you boot into the Xen kernel or the default kernel with KVM module loaded, these same tools can be used, thus providing a consistent user interface. This is just brilliant!

For existing users of Xen, should they decide that KVM is a better alternative as it matures further down the road, they could easily switch without much hassle. More importantly, its conceivable that any custom scripts (automation, failover or whatever) developed for Xen can be easily applied to KVM. This is much better than RIP-n-REPLACE in so many other "Enterprise" grade products.

Here are a few screenshots:



Cheers!