Mention Linux to a roomful of IT directors and you'll usually be told that it's the operating system for isolated techies. But increased user and supplier investment means that the penguin is set to come out of the cold and into the business environment.

Linux has become the operating system of choice for in-house development and internet services, and big investment from IBM has seen it transferring to the mainframe. This is making western European blue chips sit up and take notice.

"If people are developing on Linux, companies will be interested in it," explained Phil Dawson, program director at analyst Meta Group. He believes that Linux will have real relevance in certain key markets.

"I think that Linux can be a web services layer," he said. "We're beginning to see Linux maturing to allow scaling for all manner of processes."

It's not only internet services and in-house development where Linux suppliers are attempting to gain a foothold.

IBM has released its zSeries server with Linux for blue chip mainframe customers. "IBM has put a massive marketing push into that, but there's little client pull," said Dawson.

However, early references are becoming available. IBM recently claimed that at least 300 zSeries customers are currently piloting Linux. About 16 per cent of blue chips now use Linux on the mainframe, according to consultant Merrill Lynch.

Despite this, Dawson advises companies not to pioneer Linux technology on the mainframe. "It will take three more years before it matures, and you may need commercial support," he warned. "Remember: it's one thing getting your project started, it's another thing rolling it out to 2,000 branches."

One benefit is Linux's adaptability, as it allows the user to readily change the state of the infrastructure.

"The reason for going to Linux is to cut down your portfolio," explained Dawson. "Linux will allow you to manage the complexity of your IT systems and the number of operating systems and applications.

"Build your skills, because that's the biggest cost. Look at how you can train internally. You may even need to look to outsourcing."

vnunet.com's sister publication Computing spoke to two companies that have won a competitive advantage through Linux.

CASE STUDY: Sonera Entrum

Broadband content is bandwidth-intensive, and Sonera Entrum was keen to consolidate server resources. The Finnish telco opted to replace dozens of high-end Unix servers with a single virtual server solution running Linux.

"If you're going to run out of room because you have too many servers, virtual servers are a real way to save resources and get things running," said the company's technical director, Pasi Sutinen. "Our system is proof that you can run Linux on a mainframe."

Sonera operates about 70 virtual servers running Red Hat and Suse Linux on an IBM zSeries server. Through this solution, it provides broadband content and other internet services to home customers.

The key to Sonera's successful introduction of Linux has been sensible planning, but it's a process that has taken many years.

"We had a very careful start," explained Sutinen. "It was important that our technical staff were aware of Linux. It was already used with a number of specific in-house applications."

Sonera began using Linux in 1996. The operating system originally controlled a simple router on the telco's firewall solution. From this cautious start, Sonera has moved forward with Linux as part of a five-year plan.

"We originally had to get the best system for our needs," said Sutinen. "The operating system has had no problems and we're beginning to make the most of our knowledge."

In December 2000, the company started preparing the changeover to virtual servers. Equipment was purchased last summer and the project went live in January 2002.

Despite the planning and preparation, switching to Linux and a new virtual server farm did have some complications, the first of which was the virtual operating system on the IBM hardware.

"It's a big switch to mainframe, and we needed a big system," said Sutinen. "We had about 70 virtual servers and it was difficult to get them all networking."

Leading-edge implementation meant that integration was tough, and Sonera inevitably had to call in IBM.

"There were not many other companies using virtual servers and it was hard to get this done," he explained. "IBM did a lot of hard work and we got the system running easily in the end."

But Sutinen also believes any assistance will be temporary. "Linux doesn't need support," he stated. "We are looking for an environment where we don't need many fixes to get the system running."

There are other benefits. "On the mainframe, big systems are usually very expensive. If you run Linux it's cheaper. And it's more stable and more reliable," he said.

Using its Linux-powered virtual server environment, Sonera is able to create effective load-balancing. Now the company can run hundreds of virtual copies of Linux on zSeries servers.

"We've saved a lot of money through consolidation on one single server," insisted Sutinen. Whereas Sonera previously held a range of storage racks, the company now only needs a couple of square metres to store a single server.

Jukka Kamari, managing director at Sonera, said: "By consolidating all of our services onto one high availability IBM zSeries server running Linux we are saving resources, space and energy. It also makes systems management and maintenance significantly easier."

Sonera can switch power across its virtual servers to meet customer demand, and doesn't have to manage the hardware aspects of a high-end Unix server farm. It's a solution that effectively meets customer and business need.

"If you buy 100 servers with 1.8Ghz processors, you get power that you don't use simultaneously," explained Sutinen. "Through our build, we share the power and we're always ready to run when we need it."

Sharing power has other benefits. Non-reliance on a single server means that security is increased. If power fails and information is lost, data can easily be restored from another virtual server.

The blend of Linux and virtual server technology provides a dependable mix of hardware, said Sutinen.

"You don't need to fight with hardware solutions," he maintained. "If you compare it to Intel's solutions, it has everything you need. It has spare Ram, power and cooling processors. You can upgrade the system easily."

Beyond virtual servers, Sutinen would like to investigate cheaper forms of desktop processing. "We would like to provide virtual computing at the PC so that you don't need so many processors for each worker," he said.

For now, however, he's happy to work with his existing mix of Linux, mainframe computing and virtual servers.

"There are a lot of tuning possibilities for our mainframe," he concluded. "And if we get our parameters working correctly, Linux will allow us to use our resources more efficiently to really take the business forward."

CASE STUDY: Tradesignals

Selecting the right operating system can be a tricky business, especially when that system is responsible for powering the network that provides relevant data to online customers.

Tradesignals faced this dilemma two years ago. The Ireland-based company publishes technical trading analyses to its customers, and selecting an operating system to run in-house applications was a complicated process, according to director Stephen Egan.

"We originally partnered with Sun Microsystems and decided that Unix would be the operating system of choice," he explained. "As we expanded, we re-evaluated our technology and looked at our options."

In 2000, Tradesignals analysed three different operating systems: Sun Solaris, Windows NT and Red Hat Linux. The company's analysis compared performance across scalability, support services and total cost of ownership.

Tradesignals opted for Linux because in-house developers had already been using the system for three years.

Senior developer Donncha Ocaoimh said: "We were becoming comfortable with open source languages, and we knew where to look if a bug fix came up."

The company also believed that the operating system would provide strong business benefits. Egan maintained that Sun Solaris was two and a half times more expensive to deploy than a Red Hat/Intel solution. The systems offered similar capacity, however.

Tradesignals felt that Linux could meet strict 99.9 per cent service level agreements (SLAs) for the delivery of information to customers and partners.

"Our projected SLAs are being met comfortably," said Ocaoimh. "The system has been live for over a year and we have no regrets."

Tradesignals' system uses a range of hardware. The company receives real-time data via satellite which is collected and stored in a Red Hat-powered box. Relevant information is then sorted in a database.

The database layer connects to a real-time feed and a series of load-balanced web servers. Effective load-balancing means that user requests can be processed simultaneously.

"We can easily add extra servers if we need extra space. And if one server goes down, load balancing means that our customers' data is not in danger," explained Ocaoimh.

About 80 per cent of Tradesignals' IT infrastructure now runs on the Linux platform, including mission-critical IT and back-end databases. But migrating to Linux has created some issues.

Tying Linux to enterprise storage provided one particular challenge. "We had an issue with the drivers," said Ocaoimh. "Our programs had to be pre-compiled and the language we use for our web servers had to be sent over without changes."

It was time to call in storage supplier and business partner EMC. "They provided great help," said Ocaoimh. "Just because Linux is open source doesn't mean it can't be supported. All the problems were sorted in days."

Tradesignals is now hoping to expand the business and enlarge the network. All new applications will be on the Linux network, and Egan believes that the future for open source computing at Tradesignals is bright.

"It's no longer just for techies," he said. "It's a major deployment which we will be expanding because we chose Linux."