Some time ago, I used this Lifehacker article to add an Intel SSD to my Macbook Pro. The end of this article includes the information on how to change the disk to boot from to use the SSD as your boot drive.
What this article doesn’t mention is that this selection is just for that specific boot time. The next time you boot up, the original disk will be used.
For the last 4 months, I’ve been booting off my original disk, and barely using my screaming fast SSD drive. Since I rarely reboot this machine, and I have 8GB of RAM, the slowness of this solution hasn’t been obvious to me. Today, I installed Parallels, and this insists on being on the boot disk, so I noticed that I was booting from the wrong disk.
With a bit of poking around in Google, I found this document in the Apple Knowledge Base which tells of how to change the boot disk during boot time, and in the very last paragraph, has this useful information:
This startup volume selection is temporary. To set the default startup volume for your Mac after your computer is running, open System Preferences and choose Startup Disk from the View menu (in Mac OS X) or open the Boot Camp control panel (in Windows).
So now I’m running my Macbook Pro as fast as it should be – after performing the necessary OS updates that were previously installed on the other disk.