I have a feeling I know the answer (no), but I'm curious if there's a way to re-partition a drive or format an existing partition for Linux, without losing everything on the drive. All my drives are being used at the moment, and it's frustrating that I have space that I could use for a linux installation but can't because I don't want to lose what's on the drives.
I know that Partition Magic can repartition drives on the fly, but thats for Windows. I would imagine there is something you can get for the Mac, though.
You could repartition the drive, but not format it -- formatting a drive means that, in the very least, the partition info is wiped, and a full format zeroes all data on the disk. There are a few programs out there for the Mac that can repartiton a drive without having to reformat it first, but I strongly recommend against it. If you have a second hard drive you can connect to the machine for a while, you can use Disk Utility to create an image of your existing drive, save that image to the external drive, then reformat and partition the first drive. Then all you'd have to do is use Disk Utility again to dump that disk image back onto the partition of choice, with all your data as it was before.
Try booting off the Ubuntu Live CD. I believe there is a program on it that can shrink MacOS Partitions.
Try the Ubuntu Forums here.
Micromat Disk Studio can partition drives without reformatting. Note that it requires OS X.
But Ubuntu is free and it'll resize any HFS partition, as long as you disable Journalling. All you need is a PPC Mac. I dunno if a NuBus PPC works at all, but that'd be about the only ones.
For the records, NuBus PPC Macs don't run Ubuntu... yet.
I'm working on it, okay?
I've had plans of trying my 7100/66 G3 machine, but I haven't dug it out of the pile o' Mac. I'd guess you'd be recompiling your own kernel/initrd set for Ubuntu, or use a Debian-based setup.