Deutsche Bahn (DB), which manages the German railway system, is moving from an infrastructure based on IBM Mainframes, and Solaris, Windows and HP Non-Stop servers, to a standardised infrastructure primarily based on the Linux running on Intel servers and mainframes.
Detlef Exner, the managing director of DB Systems, said the company decided to move to Linux as part of a short-term plan to cut costs. The migration to the open-source operating system is due to be completed in 2006 or 2007.
"DB Systems has major targets to reduce costs and increase the service levels," said Exner. "One of the main strategies to achieve this is to implement Linux."
But not all applications are due to be migrated as the decision has primarily been made for cost rather than technical or strategic reasons, according to Exner.
"If we wanted to transfer everything to Linux it would cost a lot of money. We are interested in saving money in the short term -- over the next two to three years -- not over 10 years."
Applications will only be migrated if there is a business reason. Applications which would require extensive rewrites, or for which the company has recently purchased a Solaris machine, are less likely to be migrated, said Exner.
Exner said it is initially migrating applications which are available on multiple platforms, such as Lotus Notes, SAP and HP Non-Stop applications.
It has migrated some of its email servers from Solaris running z/OS to Linux, so an estimated half of its 55,000 Lotus Notes users are now being served by a Linux server. This migration is due to be completed at the end of the year as its z/OS licence is due to run out on 1 January, 2005.
DB is also migrating parts of its SAP system from Solaris to Linux, and started transferring all HP Non-Stop applications to Linux at the start of October.
Exner was unable to say how much DB would save with these migrations, but said the expected cost savings are higher when migrating from a mainframe or HP environment, than when migrating from a Solaris or Windows platform.
"The transfer of HP Non-Stop applications will result in a major cost reduction," said Exner. "Last year we compared the costs of our major platforms -- IBM Mainframe, HP Non-Stop Server, Solaris server and Windows server -- with Linux. We found out that Solaris and Windows server are quite expensive, while mainframe computing and HP are much more expensive."
Later this year DB is due to start migrating its Adabas databases and it Web server technologies -- JBoss, Tomcat, Apache and Weblogic -- from Solaris to Linux. This transfer will be finished next year.
DB has chosen to use a combination of Red Hat and SuSE Linux, as it is not obvious which is really leading the market, said Exner.
"We chose to use both as the market is not really clear -- we didn't want to back ourselves into a corner," said Exner. "Red Hat has a strong market in the US, and SuSE has backing of Novell. The market is not very clear so we wanted to be independent."
Before moving to Linux, DB set up a standardised environment for both Red Hat and SuSE Linux on both the Intel and mainframe platform to make the systems easier to install and maintain. This set-up has not only reduced the time it takes to install and maintain the servers, but has also given the company flexibility in service levels, as applications can be shifted from an Intel server to a mainframe depending on the system resources required.
"It takes three hours to set up a Linux server, while in the past it took up to three weeks -- due to standardisation," said Exner. "Also, we can easily shift applications from an Intel server to a mainframe -- we can therefore decide on the service level, if we want a high service level we use the mainframe."
As for future plans, DB may move to Linux on the desktop in the future, but nothing has been decided yet.
"We expect to make a decision in the next year -- we will see if it is profitable," said Exner. "We currently have about 55,000 desktops."