Very Strange Startup Issue...

[Tonewheel]

I have an 8 week old Mac Pro running 10.8.2. Two 2TB internal drives... main and Time Machine. Everything has been running smoothly, until yesterday.

When I boot the machine, it starts as though it was a new system install. The first screen to appear is the one asking what language I want to use, followed by "fresh install of OSX" or "restore from time machine" or "open disk utility"... you get it.

Why would my machine act like this out of the blue? The only way to boot from the main drive is to hold down the OPT key during boot and select the primary system drive. Once it boots, everything works as it should.

Help... and thanks.

 

[benwiggy]

Sounds like your Mac is not booting to the correct disk, but to the Recovery Partition instead.

If your Mac can't find the startup volume, it will boot to the Recovery Partition, which is able to install OS X, run Disk Utility, Terminal, etc.

So either there's something wrong with the boot volume, or it's just not being picked up in time. Or the RP is being actively selected in preference.

Go to System Preferences > Startup, and select your boot drive as THE startup volume.
If that doesn't fix it, then you may want to check the integrity of your system disk.
Boot to the Recovery Partition (in your case, boot up normally) and run Disk Utility to Repair the Disk. (NB Disk, not permissions.)

 

[Tonewheel]

Boot to the Recovery Partition (in your case, boot up normally)

LOL. Thanks.