Windows servers more reliable than Linux?

Slashdot discusses a survey by the Yankee Group that claims to show that Windows 2003 servers having a higher annual uptime than Linux severs.

From the article: 'Red Hat Enterprise Linux, and Linux distributions from "niche" open source vendors, are offline more and longer than either Windows or Unix competitors, the survey said. The reason: the scarcity of Linux and open source documentation.' Yankee Group is claiming no bias in the survey as they were not sponsored by any particular OS vendor."

Just because the Yankee Group has had a long and extremely profitable relationship with Microsoft, and just because their previous surveys have been heavily weighted in Window's favour, doesn't mean that this is another example of the same old nonsense. Right?

Unfortunately, the Yankee Group isn't telling where or how they got their figures. Their report is here but it includes little in the way of detail. It isn't even clear whether they found (or claim to have found) that Windows servers have 20% more uptime than Linux servers on average, or that Windows servers' increase in uptime from last year is 20% higher than Linux servers' increase. Are they measuring the length of time between reboots, or the total time running? The Yankee Group aren't telling. In other words, we don't even know what the survey is measuring.

Hmmmm.

Out of interest, Netcraft is reporting that the Yankee Groups' Win2000 webserver has an uptime of... four days (as of today, 8th June 2006). The best uptime they've seen was about 65 days -- which is a long time to hold your breath, but pathetic for a server uptime by Linux standards.