Many of you operate networks that include a variety of server platforms, which might include Windows, Linux, Solaris, AIX, HP-UX, or other UNIX-based systems such as BSD. We've seen plenty of debate over which OSs are more secure than others, but what you might not have seen is actual data that reveals which server platforms have the best uptime record and, conversely, which server platforms experience the most downtime.

Recently, Yankee Group released an interesting report, "2007-2008 Global Server Operating System Reliability Survey," based on a poll conducted with 400 corporate managers, executives, and administrators in 27 countries that asked about the amount of downtime they experienced in their network environment with 10 OSs.

AIX, experiencing a mere 36 minutes of downtime over the course of an entire year, was the clear winner at 99.99 percent uptime. Coming in dead last, and making it the new king of downtime, was Windows 2000 Server (9.86 hours of downtime), followed in the next-to-last position by Windows Server 2003 (8.90 hours). The previous year, a few Linux varieties (such as Turbolinux and Mandriva) experienced more downtime than Windows. Surprised by Windows' poor showing? Here are a few more bits of that data that might come as a surprise:

Debian, a widely used Linux distribution, experienced a significant amount of downtime (5.08 hours), surpassed only by Windows. Red Hat Enterprise Linux, SUSE Linux, and Solaris servers experienced very little downtime overall last year (1.73 hours, 1.08 hours, and 1.44 hours, respectively). Ubuntu Server, a Linux OS (based in part on Debian) that's growing in popularity by leaps and bounds, experienced only 1.10 hours of downtime on average last year, faring better than HP-UX, Solaris, and Red Hat!

According to the report, overall, UNIX-based systems reigned supreme in terms of uptime, and Linux-based system have greatly improved their uptime over the previous year.

As for Windows, downtime was worse than the previous year. According to the report, security issues are directly to blame. Yankee Group wrote, "The decline in Windows Server 2003 reliability statistics are dismaying to corporations because the Microsoft server operating system is in use at 91% of the sites we surveyed, while 74% of businesses still use Windows 2000 Server, down from 87% in the 2006 Global Server Reliability Survey."

"Upon deeper investigation, security was found to be the clear culprit. In the summer and fall when Yankee Group conducted its survey, Microsoft issued more than a dozen security alerts and patches. And to make matters worse, many of these were critical vulnerabilities. These statistics are significant because a majority of Windows servers carry the bulk of the line-of-business applications, particularly Exchange Server messaging and SQL Server databases in their firms. The increased downtime and patch management time means more work for network administrators," the report stated.

Yankee Group had some recommendations for Microsoft that I'm sure many of you will agree with: "Microsoft should get an even firmer grip on security and improve its patch management economies of scale. It is even more imperative that Microsoft do so because of the imminent release of the next generation server, Windows Server 2008. Microsoft must realize the historical 20% to 30% improvements of its predecessors to keep pace with its Linux, open source and Unix rivals. If security woes continue to plague Windows Server 2003, it will almost certainly have an adverse impact on customer deployment plans for Windows Server 2008."

Survey respondents were mostly from small and midsized organizations, described as follows by Yankee Group: "Approximately 35% of the survey respondents came from the SMBs with 1 to 100 employees, 30% from midsize companies with 100 to 500 employees, 8% from corporations with 500 to 1,000 employees, 18% from corporations that employ 1,000 to 10,000 people, and the remaining 11% percent from large enterprises with more than 10,000 workers."

I couldn't find a public link that provides a free copy of Yankee Group's report. If you're interested in obtaining a copy, you can contact the company at the URL below:

http://www.yankeegroup.com