I have a late 2009 iMac, and I am currently running OS X Yosemite. I am new to Linux, and I would like to install Ubuntu 14.04.1 LTS on my iMac and dual boot. I'm having some issues: I've been able to successfully install rEFInd, and when I reboot -- I'm able to select OS X, shutdown, restart, etc. With the DVD in the drive, I am not given an option to boot from that drive. After restarting, I forced it to load from the CD/DVD drive and was given the option of running the LiveCD or installing Ubuntu. The installation process says that no other OS is recognized and gives me options to erase everything and install Ubuntu, some others, and lastly "something else." I went into disk utility and partitioned my HardDrive from 500GB to 400GB (with 100GB free space). Any ideas?