Virtualization is a very old trend in computer science, starting in the 1960’s with IBM’s virtualization initiative. Till today virtualization has become a big player in the current computing center architecture. Without virtualization today’s computing centers architecture would look completely different – more room for a computing center would be needed, more power, more administrations costs etc – I think you know all the positive things about virtualization. But what about the real life? Does virtualization become true? Yes, it does! In this blog I will summarize which virtualization features the SAP University Competence Center utilizes to improve system utilization, reduce administration cost and improve performance for 82,000 students.
Sun Solaris Zones
Around 2006 I started my administration job at SAP UCC TUM. This was the time Sun Microsystems launched the first release of Sun Solaris, which included a very cool container technology, called zones. You can imagine a zone as a kind of container, hosting several operating system services as well as a SAP system. The main advantage of the zones are:
- Zones are light-weight
- Zones appear as a stand-alone server
- Easy maintenance and administration
- Ressource control is available to control CPU, RAM and swap consumption of a zone
- Very detailled access controls for devices
With the new filesystem called ZFS (Zettabyte File System), the zone feature became more and more interesting for me and we started to implement new SAP system inside zones only.
Starting and stopping takes seconds – not minutes!
One big advantage of a zone is the feature of starting and stopping the zone in seconds. You will love it! It only takes a couple of seconds to restart a zone. This is a big advantage compared to virtual machines, containing a complete operating system. As zones contain only several important operating system services, time to restart those services is reduced significantly. Restart time for a zone is about 10 seconds compared to 5 minutes for an entire server. Great!
I like to move it, move it
In conjunction with the new filesystem ZFS you can move a zone from one host to another one. OK, to be honest: it is a cold / offline migration. But in our hosting scenario there is no need to live migrate a database of an application server. When one of our customers encounter performance issues, the first thing we do is move the zone onto a new, more powerful server. Also in a desaster recovery scenario we move the zones. This can be done very easily – even when the source host is down. Check it out in the webcast.
Develop new ABAP programs in the production system? OK, no problem!
As students want to learn ABAP programming there is a need for some development systems. Usually universites do not want to rent more than one system at a time. Even the hosted SAP systems are used for research and teaching, students and teacher would be very disappointed when data has gone because of faulty programming. How to solve the problem? Well, zones and ZFS provide a cool cloning feature. By cloning a SAP system we can provide a SAP system for temporary development. The clone includes the same data as the productive system, so that the students can work in the clone system with real life data without any danger to teaching.
More ressources, please!
Managing ressources in virtual environments has been always an argument for the use of virtualization. With Sun Solaris you can easily manage the CPU consumption and RAM consumption of a zone. This is a very powerful feature. You may adopt the current ressource consumption to the need of the users in the SAP system. We can show you how to hibernate a SAP system to prevent it from consuming too much ressources – the syystem is still available but very slow. If necessary you can increase the ressources dynamically and boost the perfromance. To summarize: with an effective ressource control you can adopt the CPU consumption and RAM consumption to provide maximum performance for a SAP system. In our teaching environment we know the time slots when teaching takes place and so we can provide the best performance for our students.
New patches can be applied easily
One of the biggest tasks in administration life is patching a system. Patching in a zones environment means either to patch all zones or only one zone. You can decide which zone will be patched and which one will not be patched. This gives you great flexibility.
There are some other very cool features I’d love to show to you during the session. Hope to see you: http://www.sapvirtualizationweek2009.com/