MacBook Pro won't boot after defrag

Used Drive Genius 3 to defrag and now stuck on white screen with apple logo & spinning wheel. Any thoughts or suggestions.

Did you make a backup prior to using the defrag utility? Anytime you mess with the hard drive that's what you should do first.

I don't know about Drive Genius, however, iDefrag which is what I use states that after a complete defrag of the hard drive it may take an unusually long time to boot up. But after the first boot all the caches will be built again and from then on boot up time will return to normal.

Did you wait long enough for it to boot up? If you did and it still won't boot, you may be looking at a reinstall. Be sure to read the Drive Genius notes and trouble shooting tips.

Thankfully I do back up first and restored from that. Didn't know about the long boot time possibility, maybe I didn't wait long enough. I will read the Drive Genius notes. Thank you!