kernel_task (0)

The "kernel_task" is the core of the OS. It handles everything from managing multi-tasking to networking. When it is busy, that is usually because it is doing something at the request of one or more applications - which often are idle, waiting for the kernel to finish servicing their requests.

Hi, Bill and Edwin, et.al. —

Bill, Edwin has answered your question accurately.

I'm posting to add a few things, FYI.

The " kernel" is, in the simplest terms, the "guts" of any Operating System — not just OS X. Here's an article in Wickipedia that describes computer architecture, and the kernel specifically. The Kernel Programming Guide is an extensive document about this that's available from the Apple Developer Connection ( ADC), if you're interested in exploring the details.

On a more immediately practical level, the fact that the kernel_task that shows up in Activity Monitor has a Process ID (PID) of 0 illustrates that it was the first "process" that loaded. In fact, this is actually indicative of many tasks — which aren't accessible from the GUI. For example, if you double-click on kernel_task(0) to open a specific window for it in Activity Monitor, you may note that the Sample and Quit options aren't available. We can't quit it for a very good reason: everything would go haywire.

So... as Edwin has implied, wait on the kernel_task to complete its activities; things should right themselves shortly. If they don't, you may want to do a normal restart — and check in your system.log, e.g., using Console ( /Applications/Utilities/Console) to see whether there're entries that help you to discern an explanation.

If this behavior becomes chronic, please post back — hopefully, with specific description of the circumstances, what you've tried, and recent log entries that may help with troubleshooting.

Good luck!
Dean

Hi again, Bill —

Thanks for posting back to "close the loop."

And congrats on figuring out a way to get things working — "brute force" or not!

Good to hear that monitoring Console helped your troubleshooting and eventual diagnosis. Fwiw, I couldn't figure out anything useful from the entries you'd posted. Goes to show that Discussions can sometimes help "to prime the pump" — but it's often ~impossible to discern from afar what potentially key factors are contributing to a problem.

Regards,
Dean