What's New in Mac OS X 10.3 Panther
Disclaimer: although I am an Apple Certified Trainer by day, this guide is not endorsed by or affiliated with Apple in any way, nor is it indicative of future Apple Training courses. It is based entirely on my own personal experience and research. Any inaccuracies are my fault. Comments and corrections welcome at firstname.lastname@example.org.
Disk Management: the new Disk Utility
The least visible new feature in Disk Utility is that Mac OS X 10.3 now supports a journaling file system. Actually, journaling has been quietly supported for almost a year, but now there's a graphical interface for it.
Journaling is fully backward-compatible with previous versions of Mac OS. It's really just an added feature on top of the disk format, not a change to the disk format itself, so previous versions of Mac OS (including OS 9) will read and write to a journaled file system as they always have. They won't take advantage of the journal, but they won't cause any compatibility problems either. Learn more about journaling.
You can enable journaling on a volume with a single click on the "Enable journaling" button on the toolbar (there's not even a confirmation window), and you can disable it later from the File menu. Each process takes only a second or so.
The other major new feature of Disk Utility is creating and restoring disk images from mounted volumes. The old Disk Copy could create disk images; the new Disk Utility works only slightly differently. Rather than select the menu and choose from a list of devices, you select the mounted volume from the main window, then select "Image from [device name]" from the menu.
Once you've created a disk image from a volume, you can restore the volume from the disk image in the Restore tab. You can also restore a volume from a disk image stored remotely, at any web-accessible URL.
Finally, Disk Utility offers detailed information on each volume, including internal identifier names, Open Firmware device tree specification, free and used space, total capacity, number of files and folders, and information about the disk's permissions and journaling status. All the information is copyable to the clipboard and can be pasted as plaintext in any application.