Tom,
> You are asking the wrong question. The best OS is the OS you (and/or
> the customer) knows and can administer competently.
I'll have to 2nd this.
> The real
> performance differences between unices are so small as to be ignorable
> in this context.
Well, at least the difference between Linux and BSD. There are substantial
tradeoffs should you chose to use Solaris or UnixWare.
> The context switching bug is not OS-dependent, but
> varys in severity across machine architectures (I understand it to be
> mostly P4/Athlon related, but don't take my word for it).
The bug is at its apparent worst on multi-processor HT Xeons and weak
northbridges running Linux 2.4. However, it has been demonstrated (with
lesser impact) on Solaris/Sparc, PentiumIII, and Athalon. Primarily it
seems to affect data warehousing applications. Your choice of OS is not
affected by this bug.
--
Josh Berkus
Aglio Database Solutions
San Francisco