I tried to create a USB install drive for the OS X Yosemite by using the createinstallmedia provided in the installer (/Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia). However, when I booted my MacBook Pro with this home-made USB install drive, the installer says the checksum of installer file is incorrect.
I tried to use different media, the same issue remains.
Finally I made this work by restoring the Basesystem.dmg and copying Packages folder manually. Just follow the Option 2 or 3 in this article.
