Installation failed, lost disk

Ditto

My Maverick install on my mid-2010 15" MacBook Pro broke the same way. Thanks Apple. I'm away from my Time Machine so can't restore at the moment.

 

Happened to me last night.

Boot into Safe Mode (hold shift after boot chime). A bunch of disk repair and other maintenance will run (took over half an hour on mine). Once you are in your 10.8, go ahead and attach a disk and do a full Time Machine backup (sounds like you didn't have one, so this may be your last chance, do it just in case)

Reboot normally.

The Mavericks installer will boot. With any luck, your disk is now in good enough shape for it to complete successfully.

If it doesn't, you now have a Time Machine backup to restore from.

 

Happened to me, too. The Safe Mode trick doesn't work for me. Even holding the shift key, I get a circle with a line through it on the screen after the Apple logo disappears.

Guess I get to reformat and restore my backup.

 

2nd try worked

Clicking Continue from the major fail message went through the install again and it worked. Took about 30-45 minutes again, with the "less than a minute" taking 5-10 minutes. It then went through a very long gray-screen reboot but did finally. I'm now installing additional updates. Whew!