Interrupting the "Spinning Wheel of Death"?

"The beachball appears automatically when an app stops responding, and the one thing certain to cause that is disk I/O starvation. The VM system is trying to page in part of the app, and can't. The window server (which puts up the beachball) is already in RAM, and so isn't affected.

Install MenuMeters. It'll show you CPU, Net, RAM, and disk usage. I find it indispensable for figuring out which of those four limited resources is the cause of almost any slowdown."

"Run ""fsck"" (File System Check - http://en.wikipediadotorg/wiki/Fsck)

Boot into ""single-user"" mode by holding down CMD-S at startup. Hold that down and eventually your Mac will boot to a command line on a black screen. Once it's booted, type

fsck -yf

and your computer will run through the check (takes a minute or two) and will eventually finish and give you a report of either ""ok"" or ""the file system was modified"". Run it a couple of times to be sure (I've had instances where it's fixed issues, I've run it again, and it's found additional issues to fix)."

"Jeff's probably on to something. If it's affecting all of your apps, you probably have a dying HDD or some other marginal piece of hardware. I'd take it to your nearest Genius Bar and let them take a look at it.

If it's not the HDD, take a look in the at Console.app to see if there are any log entries which correspond to the times your system is hanging.

You can also run the ""sample"" utility on an app which is hung. Open up the Terminal and type ""man sample"" for more details.

If you can track it down to a fairly consistent issue (software-based), please file a bug at http://developer.apple.com/bugreporter/ (will require a free ADC account).

One more thing - if you have a copy of your partition (usually by using the restore feature of Disk Utility), you can boot from an external drive. Try restoring your system partition to an external drive and then either use the Startup Disk pref pane or reboot holding the ""Option"" key to pick your external partition to boot from. If the spins stop, it's a pretty good sign that something's wrong with your internal HDD or your filesystem."

"Eliminate hardware errors first - put the system disks in and reboot holding 'd' key down.
Run the extended hardware test, it will take several hours so do it overnight.
It will spit out a weird code (if it finds a fault), if it had HDD in it - your hard drive's faulty. If you get this immediately clone your drive with SuperDuper or equivalent.
You can use Tech Tools Deluxe if you have the Applecare - but it's not as good in my experience.

Then try running disk utility - it can do a check from a live instance of the OS, if it finds a fault you repair by using the system disks and booting from them holding down the 'c' key this time. If Disk Utility won't fix a fault, either re-install OS or use DiskWarrior (budget depending). Repair permissions while you're about it, it can't hurt.

Then check the console for errors as suggested in another post. If you narrow the problem to a single app, re-install it (use something like AppZapper to clean out the preferences).

This is a good resource http://www.macattorney.com/ts.html"

"The base os very robust, it's usually the GUI that hangs.

If you can manage to log out, everything should be fine again. I have a script ""flogoff"" that I run (from Terminal if I can still get there, otherwise via SSH) that kills my login and brings back the login screen. That usually works.

Update: Found it:

#!/bin/sh

pid=`ps auxc | grep $USER | grep loginwindow | cut -c 10-14`
sudo kill -9 $pid

Until 10.5 the kill didn't need a sudo. In 10.6 users are apparently not allowed to kill their own login.

Oh, and always, ALWAYS, keep Terminal.app open! Finder.app is just not robust enough and uses every opportunity to show the SWoD."