Formatting a Partition


This version of iPartition can only format Mac OS (HFS), Mac OS Extended (HFS+) partitions (including the case sensitive and journalled varieties), FAT16/FAT32 filesystems and NTFS filesystems. Future versions are likely to include support for other filesystems.

To format a partition

  1. Select the partition you wish to format.

  2. Choose “Format…” from the Partition menu.

  3. A sheet will appear prompting you for more information.

  4. Pick a name for the new volume.

The remainder of the sheet will vary depending upon the filesystem type. For FAT filesystems, you can only enter the name but for HFS filesystems you can choose the type of HFS volume you want.

If you have selected Mac OS Extended (HFS+), then you can also choose to create a filesystem wrapper, to enable journalling and/or to create a case sensitive filesystem.

A filesystem wrapper is required if you wish to boot Mac OS 9 or earlier from an HFS+ volume. It also improves the user experience if a user tries to access a disk with a system without Mac OS Extended (HFS+) support by providing a Readme file explaining how to access the data on your disk. Apple’s tools always create a filesystem wrapper, however Mac OS X does not require one and the wrapper can take-up a fair amount of space on your disk (several megabytes for a large disk).

The other downside of using a wrapper is that if you anticipate resizing the volume, the presence of a wrapper during a resize can force iPartition to move the entire contents of the volume to a slightly different place on the disk due to the fact that the wrapper may change size when you resize the volume. This can easily double the time taken to resize a partition. In general, we recommend formatting without the wrapper if possible.

Journalling is only supported on Mac OS X 10.2 and above. iPartition can format journalled partitions, but currently does not use the journal itself.

Case sensitive filesystems are only supported by Mac OS X 10.3 and later. Note that it is a good idea to use a partition type of HFSX (Mac OS Extended) instead of HFS/HFS+ (Mac OS Standard/Mac OS Extended) when using case sensitive filesystems, as this may prevent some poorly written disk utility software from attempting to “repair” what it sees as problems with the volume.