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No rEFIt menu after Safe Sleep or power loss

Problem: When a Mac comes back up after a power loss, Safe Sleep, or Mac OS X kernel crash, there is no rEFIt menu.

Solution: This is intentional, and protects you from data loss.

When a Mac wakes from Safe Sleep, it actually goes through a regular boot process. Only after the Mac OS X kernel takes control, it notices that there’s a saved memory image on the hard disk, and loads it. It is a bug in the interaction between Mac OS X and the Mac firmware that users can interrupt this process and boot a different operating system. rEFIt tries its best to prevent this, because in this situation the file systems on the hard disk are in an inconsistent state, and using them from another operating system can result in corruption and data loss.

This behaviour is made possible by the “rEFItBlesser” Startup Item that is installed by default when you use the installer package to install rEFIt. When Mac OS X starts up, rEFItBlesser sets the boot options to boot directly into Mac OS X. When Mac OS X shuts down cleanly, rEFItBlesser changes the setting back to point at the rEFIt menu. (This mechanism also lets you install rEFIt without having to run enable.sh manually.)