Yesterday I went to open a file on an external hdd and finder hung. I used activity monitor to force quit and then tried to reopen finder, but got the message "the application finder.app can't be opened -10810". Googling I found snow leopard seems to have a problem w/ external hdds , usb & 1394, and network shares. This has been my experience - snow leopard has hung 2 or 3 times since August, always when I had an ext hdd attached. I thought maybe the drive itself had a problem, but this was another ext hdd.
There were several different suggestions to try and restart finder and avoid having to shutdown via the power button [hard reset?] and to prevent the problem in the future. One was to unmount any ext hdds w/ the command
sudo umount -fv DRIVENAMEor
sudo umount -Af. Or you could use
sudo killall Finder Dockto force Finder & Dock to quit and relaunch.
I tried reading the man page on sudo,only understanding the first line - that it "allows a permitted user to execute a command as the superuser or another user, as specified in the sudoers file". I don't understand why or how the sudo command is used in the above unmount and killall commands. Do these commands require a superuser password? [That's the same as the root user, right?]
Other suggestions were
/System/Library/CoreServices/Finder.app/Contents/MacOS/Finder &in terminal
To turn the ext hdd off and back on [you can't eject them once finder crashes - they don't show on the desktop].
Exclude ext hdds from spotlight indexing
Delete finder & disk utility plist files
Rebuild launch services
Most of these suggestions were for 10.6.1, but it seems like updates haven't fixed the problem. Does anyone have any suggestions on what to do in what order if/when I encounter this problem again?