restarting from ubuntu in mac OS X

It's not actually true that the Ubuntu CD does not touch your disks. In fact, it does not touch them automatically, but if you tell it to do something with them, it will do. So, first of all, are you haven't modified your hard disks while trying the live CD?

May you paste the exact message that tells you to reboot your computer? Also, when you see this message, do you see also a logo or something?

In the meantime, here's what I suggest you to do to protect your data: run again the Ubuntu live CD and copy all your files and directory to a backup drive. In this way you will be able to work with your files on a different computer.

Thanks and sorry for the inconvenience.

Dear Andrea,

Thank so so much for an answer! I´m at witś end at the moment as I can´t get
into my own work.... aaaaarch!

Yes, I did change a few things, mainly to get a link to the Net! So, I
filled in my netwerk data (thank god Ubuntu had enclosed Firefox!) to get
onto the ubuntu-community and gmail. But that was all; no user names or
passwords, nothing else, just the network.

When restarting with Option or with an original Mac system (Panther, Tiger,
Leopard) in the CD-tray I am getting the exact message and NO logo:

*no bootable device - - insert boot disk and press any key*

My data are safe, the problem is I need desktop publishing and illustration
programs (XPress, inDesgin, Photoshop etc.) to use them.

I love to hear the beginning of a solution ;-)

Kind regards.

Johan-Martijn

So, the "no bootable device" is a good thing. It basically means that it does not known where the operating system is, but all the other stuff should be OK. It's a bit strange that the Ubuntu live CD caused this, but anyhow here's how you can fix this problem.

Please note that I don't have a Mac, and the solution I'm proposing is the one that I found an almost every web page I read about this kind of problem. It should work, but I won't be able to give you detailed instructions, sorry.

So, as soon as you boot the computer, press Option and keep holding it. After a while you should see a gray screen with some icons. Here you should select "Macintosh HD". At this point, Mac OS should be started. Now you should just tell it to use the Macintosh HD every time. You should be able to do this from System Preferences → Startup Disk.

I hope this helps; if not, just ask.

Hi Andrea,

Sadly, when I'm getting the gray input screen via Option, I'm confronted
with a massive lock and not a single choice in sight (sigh), no Mac HD's,
not even Ubungu itself. Anyhow, I've found more stranded users from the Mac
community, though none of the answers are very clear.

The main point is that the Mac and Ubuntu are quarelling over the allocated
hard drive boot tracks. There seens to be a programme - called reFIT - that
could help us, though nobody seems to know from which platform you have to
use it. Well, I've my work cut out for me in the weekend. In the meantime I
appreciate your help!

Kind regards,

Johan-Martijn

Hi, it's complicated because Mac G5 doesn't BIOS and MBR on start of disk, but EFI and GPT with backward compatibility with BIOS/MBR. So solution described for PC doesn't work on Mac. You must use only data from Mac's forum.
For reFIT, I went on their website and you need any platform, as reFIT is a bootable disk which is its own platform.

The Ubuntu program Gparted (upper bar, System->Administration->Gparted) managed EFI/GPT, even if Ubuntu doesn't. You could use this program to check if your HFS partition is always bootable, and add flag "Boot" if doesn't. But I have no Mac! Best is to go through Mac forum.