"Preparing to remove partition"

I briefly tried Ubuntu on my PowerBook G4 and haven't touched it since, so decided it was time to free up those partitions for MacOS.

Enter the problem... Click the partition in Disk Utility, click the minus button, and apply... and it hangs, forever, no messages in the log, just hangs at "Preparing to remove partition." Even tried booting from the MacOS Install CD, same thing. There're quite a few posts about this online. Most seem to think that using Ubuntu's partition manager somehow caused the problem... Most suggest backing everything up and writing a fresh partition table from Disk Utility on the MacOS Install CD, then doing a restore from the backup. Others suggest using linux's partition utilities from now on... (which is silly if you're trying to *remove* linux).

I've figured out a trick, I guess... resize a partition (using Disk Utility). Not sure if it matters which one... as long as it's possible to resize it. Best-bet, erase/reformat the unwanted (ubuntu) partition into a Mac resizeable format (Mac OS Extended, Case-sensitive, Journalled, in my case). Resize that partition to something smaller. Afterwards it seems to delete partitions as expected. (Hopefully I didn't jinx myself by saying that and it still boots next time!)

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Turns out it's a tad more complicated if you want to do more than just delete the partition (and why would you want to do that, instead of just reformatting, unless you planned to make new partitions of different sizes, or merge two partitions, etc?).

In my case, the Ubuntu partition was somewhere in the middle of the drive, and I wanted to merge it with later partitions to make one large partition. (This is a feat in itself, because merged partitions will only keep the data from the first in the partition-list... read below) Here's a link that got me started: http://macheist.com/forums/viewtopic.php?id=15828, and another: http://ubuntuforums.org/showthread.php?t=1181936

First: Run "diskutil list" from the terminal... (and "man diskutil"!)

And, a handy trick I discovered in the first link, create a blank disk-image, create a partition-table similar to the one you're planning to modify, and try everything you're planning to attempt inside that disk-image first. (Handy for making sure the merge command is going to keep the files on the first partition, among other things... like discovering that "eraseVolume" does not erase the volume from the partition table, but reformats it.).

The problem with creating a new partition and/or merging, at this point, arose because of the *hidden* "Boot OSX" partitions located before each partition, and the "Apple_bootstrap" partition created by ubuntu. These were not deleted with the deleted partition(s) with which they were associated, and are located in the space that otherwise appears empty. "Partition failed with the error: MediaKit reports partition (map) too small." I have no idea how Apple even thought the resize function could work in this case... (I can't recall how, but long ago I set up Disk Utility to show hidden partitions. This can also be done via diskutil in terminal).

As I recall, I ended up reformatting the BootOSX partitions into a usable-viewable format, then merging into/past them (more on merge later). Alternatively, and more intuitively, after reformatting (in Disk Utility, if you can figure out how to show hidden partitions), they'll show up in the partition-list and can be deleted. BEWARE: The BootOSX partition associated with your OSX partition is *necessary for booting* so be sure you know what you're doing! As far as I can tell, the "Boot OSX" partition that's located *immediately before* the OSX partition is the one that boots it, but I don't know this for certain for all cases.

As for merging two (or *multiple*) partitions, look into the man-page for diskutil. (The terminal command is: diskutil merge "format type" "name" disk#s# disk#s#) The format-type and name are necessary, even if you're not planning to reformat, it doesn't seem to affect the drive if everything's right.

Notes: I'm running 10.5.8 (Leopard? Tiger? Bobcat? Puma? I have no idea) on a PowerPC G4. These BootOSX partitions may vary a bit on intel, I don't know. Also: "Disk Utility" is the one located in Applications/Utilities/Disk Utility, and "diskutil" is a terminal (command-line) program akin to fdisk with a bunch more features).

Hope this helps someone!