update OSX Yosemite & cksum mismatch After OSX Update -> Yosemite:
No option to login and run the system.

Via Firewire (T) and Diskutils &amp;&amp; Diskwarrior:
"Unvalid Disk-Label @ 499239710720: cksum mismatch"

Diskwarrior: no option to rebuild
Diskutills: Unvalid Disk-Label @ 499239710720: cksum mismatch

What could I do to reboot and rerun the machine? How to fix this problem?
You might have invalid Yosemite Installer package.

Try the Command+Option+R during boot to recover it from Internet.

To check the flie run following in the Terminal

shasum /Applications/Install\ OS\ X\ Yosemite.app/Contents/SharedSupport/InstallESD.dmg


The result should be:

eebf02a20ac27665a966957eec6f5e6fe3228a19  /Applications/Install OS X Yosemite.app/Contents/SharedSupport/InstallESD.dmg


Do this before running the Install.