John Alberg, vice president of engineering at Employease Inc., is typical of many IT managers nursing budding relationships with the Linux operating system: He loves it; he loves it not.
Alberg loves it as a relatively stable platform for running selected enterprise applications. About a year ago, the Atlanta-based human resources application service provider switched from Windows NT to Linux on its application server layer, where it has some 25 dual- and quad-processor Dell Computer Corp. PowerEdge application servers. "This is basically the workhorse of our network, and we switched primarily due to stability issues," Alberg said. "Our system is about 100 times more stable now than it was with NT."
That was a big step. But Alberg isnt ready to consider making Linux the platform for all his enterprise applications. First, he wants to see better security and proven SMP (symmetric multiprocessing) scalability.
"Linux does not yet have the extensive security features of some of its Unix competitors, like Suns Solaris," Alberg said. "We use Solaris on the external proxy layer that is exposed to the Internet. I want wholehearted vendor endorsement and a couple of years of solid quality assurance testing by companies like Oracle [Corp.] before I allow Linux to take over my database server."
Its a common refrain among IT managers today. For as far as Linux has come—and the release of the Linux 2.4 kernel earlier this month has brought a range of additional enterprise functionality to the open-source operating system—there is still a way to go before it becomes a true mission-critical, enterprise-class system that can effectively compete with the Unix and Windows platforms.
While users, vendors and analysts agree Linux has made great strides on the Web server side, they admit it still falls short when it comes to supporting workloads required by applications like ERP (enterprise resource planning), business intelligence, CRM (customer relationship management) and supply chain planning, as well as the ability to run multiple, mixed workloads on large SMP servers.
Michael Tiemann, chief technology officer at Linux vendor Red Hat Inc., in Durham, N.C., summed this up recently. "While there are many definitions of what constitutes an enterprise-class operating system, I think it would be fair to characterize Linux as a rookie Tiger Woods, full of potential that has yet to be realized," Tiemann said.
How long it takes to fulfill that potential depends on several factors, among them: how quickly the 2.4 kernel is adopted by commercial distributors and how quickly the development cycle for Version 2.5 gets under way.
Greg Olson, the co-founder and chairman of Sendmail Inc., in Emeryville, Calif., which uses an IBM Linux mainframe for development and runs a host of Linux servers, wants more enterprise features. Olson agrees that Linux is clearly enterprise-ready at the server level for certain applications like e-mail, e-commerce and Web servers, but he said it lags with regard to running other mission-critical applications like financials and CRM.
Those will emerge over time only if an increasing number of companies demand a unified Linux platform, Olson said. "I welcome the ongoing development work to make Linux more robust and scalable. The initiatives that allow Linux to effectively host 100 million mailboxes and run huge backbones for mail systems are exciting for us," he said.
Beyond the 2.4 kernel, Linux developers are asking for the incorporation of a journaling file system, more work on Linux clusters and on the scheduler, additional scalability, high availability, internationalization, and printing and systems management.
While a few IT managers are beginning to move critical systems onto Linux, others, like Richard Smrcina, data center manager for Grede Foundries Inc., in Milwaukee, say they first need to see further enterprise-level capabilities.
For the past year, Smrcina has been running Domain Name System, mail, network monitoring and other applications on an IBM S/390 Multiprise 2000 system equipped with SuSE Inc.s Linux Enterprise Server. Eventually, hed like to consolidate other applications such as DB2, WebSphere Application Server and Apache-based systems from other platforms onto the Linux mainframe. Hed even like to move Gredes PeopleSoft Inc. PeopleSoft 7 ERP systems, currently running on IBMs AIX Unix operating system, to the Linux environment.
"The potential going forward to consolidate those machines onto our [Linux] mainframe is desirable and, hopefully, with PeopleSoft 8, we can do some of that because this is more of a Web-based application, and the potential to use Apache to serve those Web pages will be a huge bonus," Smrcina said. "I was somewhat skeptical about Linux and its enterprise capabilities until I started using it. The performance has been solid and reliable, opening up a whole new world of application possibilities for us."
The enterprise capabilities found in the 2.4 kernel, which will hit the market later this year, are clearly a large step in the right direction. One of the most significant features is SMP scalability. While the kernel has a CPU limit of 64 processors, it is expected to be mostly used at the eight-way level.
Also included in distributions based on the 2.4 kernel will be large-file-system support; the ability to address up to 64GB of physical memory on Intel Corp. X86 servers and IA-32 platforms; expanded hardware support, with various new drivers for hardware like Universal Serial Bus and three-dimensional accelerated graphics cards; and various new architectures such as IBMs S/390 mainframe, the IA-64 and, eventually, Advanced Micro Devices Inc.s X86-64. While the Linux backers are excited about the increased scalability of the 2.4 kernel and other developments such as the appearance of new, enterprise-class development tools for the operating system, they say the platform needs further work.
But whatever shortcomings Linux may still have at the enterprise level, its phenomenal growth has surprised even the most bullish observers. Once dismissed by major software vendors like Microsoft Corp. as a niche operating system on the fringe of the mainstream that would appeal only to a small core of developers and engineers, Linux has become a force to be reckoned with. Microsoft CEO Steve Ballmer this month publicly said that Linux was his companys greatest threat going forward. And IBM is committing $1 billion to its Linux initiatives this year.
Stacey Quandt, an analyst at Giga Information Group Inc., in Cambridge, Mass., said the 2.4 kernel, with its increased technical enhancements, including logical volume management, raw I/O and enhanced SMP scalability, goes far toward closing the gap between Linux and midrange Unix.
"But for Linux to truly cross the chasm beyond characterization as a workgroup and departmental solution, it needs to be capable of supporting workloads like ERP and CRM," Quandt said. "Kernel development is only one of the steps in this process. Enterprise-class system software supported by ISVs and OEMs is the other part."
Even with the enterprise-oriented 2.4 kernel in place, that support will take some time to materialize. But IT managers whove become encouraged by the potential of Linux should be willing to wait. After all, enterprise-class operating systems arent made overnight.