Beagle is Gnome's answer to built-in desktop indexing and search. The heart of Beagle appears to be beagled, the Beagle daemon. I went out earlier today to run a number of errands leaving europa on and running with openSuse. When I returned home several hours later, I came back to an unresponsive machine. The display was corrupt, with random pixels all over the screen. No jiggling of the shift keys on the keyboard or the mouse would bring up the desktop.
I quickly noticed that the hard drive activity light was on constantly. I switched from hitting the Big Red Switch to attempting to gain access to a basic text-only window (Ctrl Alt F1) and logging into root. I wanted to find out what was happening on the system. I hit CAF1 and waited about 30 seconds before the screen cleared and I got a login prompt. Good! I had to wait another 15-20 seconds to log in as root and get a shell prompt. I fired up top and saw that beagled-helper had 99% of the CPU. I killed it not once, but twice; it restarted the second time as I was watching top. Once beagled-helper was fully dead, europa's normal responsive returned.
When I got control of the graphical desktop again I ran free in a terminal window to see how much swap space got chewed up. As I suspected, beagled-helper had eaten up a good chunk of swap; nearly 200MB worth. Under normal circumstances my system uses an order of magnitude less, and that's with Java and/or a number of gcc compiles running on other desktops. I don't know what beagled-helper was doing, but the high swap use coupled with whatever it was attempting chewed up CPU cycles and hard-drive bandwidth.
My final step is to hunt down and keep beagled and beagled-helper from ever starting again. It's not a part of regular services, but looks to be started by something within the KDE login process. And for the record, there is an Ubuntu bug (64326) that was logged against a similar problem back in October. Whatever, I don't see a need for this, and I will shut it down permanently.