More on drives refusing to unmount; solution from Symantec
Devices refusing to unmount: Force quitting the Finder may resolve
Devices refusing to unmount: USB 2.0 also affected by Norton AntiVirus?
Mac OS X 10.4.2 Special Report: FireWire/USB volumes refusing to unmount
Mac OS X 10.4.2 (#10): FireWire drives refusing to unmount, solutions; Mail.app 2.0.2 password/send solutions; more
OS X Odds & Ends: Timbuktu security leak?; Disk image does not unmount
FireWire drives automatically unmount with logout in Mac OS X 10.3.x, workaround
Mac OS X 10.3.7 (#9): Slow Safari startup, clearing caches; DiskWarrior causing drives to spontaneously unmount?; more
Troubleshooting Security Update 11-04-2003: Unmount secondary volumes before installation
If you have a new hard drive to use with your Mac, there are several considerations to keep in mind for its optimal use.