Snow Leopard and Ubuntu 10.10

Up until a week ago, I had never owned a Mac before. Anyway, last week I bought a Macbook Pro i7, the first time I booted it up I thought to myself "I feel lost". The second time I booted it, I installed Ubuntu 10.10 straight off a DVD included on the front of a Linux Format magasine via boot camp - I'm use to using Linux, and thought I would use that as the main OS and break myself gently into the Mac OS over a period of time (turns out that I've got use to the Mac OS a lot faster than I thought I would and really like a lot of its features).

Anyway, the Linux install was successful... after a fashion. The problem I have now is that Linux boots as the default OS - I have to hold down the alt key in order to select the Mac OS.

Having had a quick Google search, I found that if I boot the Mac OS and go to:

Settings->Startup Disk

I should be able to reinstate the Mac OS as the default OS. However, the Startup Disk utility does not show the Mac OS as an option, it only shows "Network startup" and nothing else (Linux does not show up either).

So, I had a look at the partition table under Linux using GParted and I've noted that there a three partitions that are Mac related. One is labelled as Boot Camp, another is EFI and the last is Mac HD. At the moment the EFI partition has the boot flag against it.

Does anyone know how I can reinstate the Mac OS as the default OS? Should I move the boot flag? I'd rather not have to reinstall the Mac OS, everything is running fine aside from the fact that I would like the Mac OS to be the default.

This is a known problem when installing Linux. The Mac boot sector sometimes gets overwritten. A Mac formatted hard drive has two standard partitions: The first is the EFI (small 200 MB) and the second is the main data partition. The EFI partition should have the boot flag so don't move it or edit it.

First thing to do is to try and reset the PRAM - NVRAM. See this Apple KB article and follow the instructions: LINK

Post back and let us know if that works. If it doesn't, we can try something else.

Thanks chscag, your idea worked. The Mac OS is now the default and I can access Linux by holding down the alt key at boot up.

Just a couple of notes for anyone who is interested. Resetting the PRAM didn't go quite the way that Apple said it would. When I held down the Cmd, Option, P and R keys directly after pressing the power button, I apparently should have heard the Apple sound, then shortly after I should have heard it again (after a reset I assume) at which point I should have released the keys. However, that is not what happened with my Macbook i7, instead I heard the Apple sound, shortly after that the screen went black, and stayed that way for a couple of minutes, at which point I figured there was something wrong and so I held down the power button until the machine switched off. Upon switching it back on, I quickly realised that the PRAM reset had been successful as the Mac OS now boots as the default.

Anyway, everything seems OK. Thank you chscag once again for your help, it is much appreciated.

Thanks for posting back. Have fun and visit often.

Actually it is easy fix. Throw your SL disk and run it. After this you want to go into disk utilites and click on the HDD with prob and click repair. The sectors will be fixed takes 2mins tops. Turn reboot computer and your good.