Mac OS X Volume Formats


Mac OS Extended – Default for Mac OS X, journaling enabled file system. This is also the recommended format for new installs. Also called HFS Plus. The Journaling feature in Mac OS Extended was first introduced in Mac OS X Server 10.2.2

Mac OS Standard (aka HFS -Hierarchical File System) – Older standard that is not very popular, and inefficient when compared to Extended. OS X can read a HFS volume but the OS cannot be installed on one.

UFS UNIX File System -Supported in OSX, and may be of use to UNIX developers. Only use this if there is a specific reason for it. Apple notes that AirPort does not function when OS X is on a UFS volume.


FAT -Windows compatible file system– allows files created to be used in both Mac OS X and Windows. Not supported for boot volumes.

Mac OS X Extended’s journaling feature creates a continuous record of changes to the file system in an attempt to have a restore record available in the case of a fault or loss of power. This feature is recommended for server and critical data protection, as it may incur a performace hit to the machine. It can be turned on or off using Disk Utility. You can also check the current volume format type using Disk Utility, along with a view of overall capacity and free space.