From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20021218 Description of problem: GRUB location must be selectable as either MBR or /. Currently overwrites MBR, destroying user's boot manager. Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1.Install a boot manager, such as BootItNG. 2.Install phoebe. 3.Restore the MBR to the original boot manager. Actual Results: Anaconda rudely gives only the choice of overwriting the 3rd-party boot manager MBR or booting off floppy. Expected Results: Anaconda must allow retention of the 3rd-party boot manager by specifying an alternate location for GRUB, such as /. Additional info: Other distributions offer a choice of putting GRUB in the MBR, or in / allowing 3rd-party boot manager to retain control.
This is configurable from the advanced boot loader options screen