Is Linux ready for Mission Critical Systems?

There are many examples were senior managers are totally unaware that Linux already plays a significant role in Mission Critical Systems, and has done so for several years.

In the recent article Open Source Poses “Huge Risk” To Organisations the CIO essentially said that Linux was not suitable for Mission Critical Systems, though the article goes on to say how the company GE already uses a lot of Open Source Software:
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Responding to a question from eWEEK Europe UK on the first day of the Central and Eastern European IT Leaders Summit & Expo, in Budapest, Peter Gyorgy, chief information officer of GE's Consumer and Industrial division in Europe, said non-proprietary code presents a significant risk to companies.
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The following article shows how much more that GE CIO is out of touch with reality Newsflash for GE, you're already using 'risky' open source:
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First, it's ridiculous to suggest that because something is "low cost" it is inherently risky. Gyorgy seems to believe that the more he spends, the safer he is. Last time I checked, Google et al. were running their networks at more significant scale than GE, and all on open source.

Maybe Gyorgy simply doesn't like equal or better performance for less money. In this, he's apparently alone. The 451 Group's survey data has roughly 90 percent of the 1,700 IT executives surveyed declaring that they have realized cost savings with open source. These are IT executives that a few years ago might have shared Gyorgy's views on open source.
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In the article The CIO is the Last to Know a CIO was totally unaware that his Data Centre already used Linux in 25% of the servers!, and that was written in 2002 - now Linux is even more widespread.
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It always happens this way with new technology. As the leader of North America sales for Red Hat in 2002, I remember calling on the CIO of a company in the financial services industry that processed millions of transactions daily in support of the equities market. I sat in his office while he explained to me that his operation was mission critical – the markets depend on this operation. He would never consider using Linux and open source. “Why don't we take a tour of the datacenter,” he asked. I was game, so I replied “Sure.”
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