How to limit the size of Time Machine backups to Time Capsule

Many have expressed the desire to partition the internal hard disk in their Time Capsule -- presumably because they wish to limit the amount of space allocated to Time Machine backups. I myself wanted to do this. Thanks to instructions posted at http://www.readynas.com/?p=253, I believe I have found a solution. Note: although it is working for me, this is not guaranteed to work, it may contain errors, and it is not for those who are unfamiliar in working in Terminal. I also do not offer tech support. You're on your own. With those provisos, here are the instructions:

1. In System Preferences, turn Time Machine off.
2. Find the MAC address of the machine’s internal Ethernet port by typing at the prompt (not including quotation marks:
"ifconfig en0 | grep ether"
This should produce a single line of output, such as:
ether 00:16:cb:af:91:d7

Even if the network backups will be done using a different port (e.g. AirPort: usually “en1″) the system will use the address of en0 as part of the system identifier.

If your computer's (not your hard disk's) name is "Mac", the identifier that Time Machine will use is “Mac_0016cbaf91d7"

3. Create a new sparsebundle directly on the Time Capsule share. Decide how many gigabytes in size you want it to be, and substitute the figure you want for "125" below. Be sure to append the "g" for gigabytes. The easiest way to do this is to type after the prompt:

"hdiutil create -size 125g -fs HFSX -volname "Backup of Mac"

and then, *without hitting return*, dragging the Time Capsule volume appearing on your desktop directly from the desktop into the Terminal window (assuming you have the Finder set to display connected servers). So if the name of the Time Capsule volume is "david", the final command should look something like this:

hdiutil create -size 125g -fs HFSX -volname "Backup of Mac" /Volumes/david/Mac_0016cbaf91d7.sparsebundle

Note that in place of "david" would be whatever the name of the particular Time Capsule volume you have chosen (I use "Secure Shared Disks: With Accounts" under Disks > File Sharing in AirPort Utility , so volumes for each account name are created).

Hit return. You should see:

created: /Users/david/Mac_0016cbaf91d7.sparsebundle

4. Now double-click that .sparsebundle file residing on your Time Capsule volume, and it should mount.
5. Launch Disk Utility
6. Choose "Backup of Mac" in the Disk Utility sidebar
7. Click on the button "Enable Journaling"

Note: the reason why I do this is because in the course of testing, I found that Time Machine created .sparsebundle files which when mounted had filesystems that were both case-sensitive and journaled, and the hdiutil command apparently doesn't allow one to create a .sparsebundle file with both of these attributes simultaneously.

8. Unmount "Backup of Magpie"
9. Open the Time Machine prefpane, and select "magpie" as the new destination for Time Machine backups
10. Turn Time Machine on