I'm in the process of setting up some production
VMWare instances on an ESX box. My OS of choice
is Ubuntu, which forms the cornerstone of my
environment.

BUT: I'm forced to run RHES 4.5 for a particular
application. Well, actually, I'm running CentOS
4.5, but you know what I mean.

The RH kernel is 2.6.9-55.0.2.ELsmp, and the Ubuntu
kernel is 2.6.15-26-server.

Each is allocated an almost identical VMWare instance.
4 CPUS, 4 GB of memory, 60 GB of disk, 2 network adapters,
default priority assignment.

The Ubuntu box is running a lot more "stuff". Samba,
lots of netmounts, lots of processes looking at directories
both local and via the network to execute against, users
logged in running my menu and bash, etc. As I said, it's
the workhorse, and a lot of what it does all the time is simply
looking for more work todo.

The CentOS box does almost NOTHING until called upon
to execute a particular task.

So I watch the idle steady state CPU MHz consumption in the
VMWare performance monitor, and I see Ubuntu consumes 40Mhz
while CentOS eats 200Mhz.

WTF?

Neither is running X, and watching in top shows equally idle
systems.

Any idea why the huge difference? While this may not be a
major issue, I'm wonder if there is anything I can do to
tweak it down.