This article has been archived and is no longer updated by Apple.
What kinds of partitions can be resized in Mac OS X v10.5 Leopard?
Mac OS X v10.5 Leopard can resize any disk partition except a Master Boot Record Partition. You can use Disk Utility to see if a partition is a Master Boot Record Partition, and also to resize eligible partitions.
Important: Resizing a Master Boot Record partition will erase all data on it, so be sure to back up important files on affected partitions first.
What is a Master Boot Record?
A Master Boot Record, or MBR, is the first sector of a partitioned disk volume. It contains information about how how your disk is partitioned. See this article for some advanced details.
Here are some third-party websites with more information:
Important: Mention of third-party websites and products is for informational purposes only and constitutes neither an endorsement nor a recommendation. Apple assumes no responsibility with regard to the selection, performance or use of information or products found at third-party websites. Apple provides this only as a convenience to our users. Apple has not tested the information found on these sites and makes no representations regarding its accuracy or reliability. There are risks inherent in the use of any information or products found on the Internet, and Apple assumes no responsibility in this regard. Please understand that a third-party site is independent from Apple and that Apple has no control over the content on that website. Please contact the vendor for additional information.