macospartitionsnow leopardupgrade
I have Macbook6,1 Late 2009 Unibody white Snow Leopard with dual boot Debian Wheezy installed on the other partition.
I use EFI to show boot options at startup.
Will upgrading to Mavericks overwrite/delete other partitions?
Debian is what I use primarily. I would however like to upgrade to Mavericks for security reasons.
There should be a point—after you choose the language, but before it starts trying to install the OS—where you see a Utilities option in the menu bar.
Do you get to this point? If so, what happens when you choose Disk Utility?
There's more information about this at Using Disk Utility to Repair a Disk (University of Wisconsin).
OK, now it's a different question, so here's my different answer:
If repairing your main partition is what you want to accomplish, why not just run Disk Utility off the 10.5 system disk?
It should be fine. Just make sure to select the right disk (Macintosh HD) when installing Lion. A backup never hurts, either.
Best Answer
Updating will not affect any partitions you do not choose in the set-up process. If you're not asked, then it will install on the partition the OS X install originated on.