For those with a lot of footage or projects clogging your hard drive, iMovie '09 made declogging substantially easier by letting you store both events and footage on external drives. But there are some limitations, mysterious in nature because the iMovie documentation doesn't detail them. If your external drive is connected, shows up in the Project and Event lists in iMovie, but has a yellow caution symbol next to it, let's dispel the mystery with two important tips:
- Your drive needs to be formatted as Mac OS Extended or Mac OS Extended (Journaled), formats otherwise known as HFS+. If it's FAT-formatted, for example, you have a drive that iMovie will display in its list while taunting you with the caution symbol. If this is your problem, you'll need to use Disk Utility in your Applications->Utilities folder to reformat the offending external drive. Remember, "reformat" is the obscure technical term for "ERASE!"
- Your drive needs to be fast enough. Where does iMovie draw the line? Well, thumb drives and network drives are automatically disqualified. Editing video requires a lot of bandwidth between your computer and the drive storing the video footage. Thumb drives and network drives are usually too pokey. I'm told you can overcome this limitation with symbolic links, but at your own peril. If you don't know what symlinks are, this will tell you more than you need to know.