ARCHIVED: What is the Mac OS Extended Format?
The Mac OS Extended Format, also known as HFS+, is the primary volume format for Mac OS X. Some of its features include:
- Because it uses a 32-bit address to store data, HFS+ can assign
more than four billion allocation blocks to a volume. As a
consequence, the minimum file size for even very large volumes remains
small, usually around 4KB. With some HFS+ formatting utilities, the
minimum file size is as little as 512 bytes (i.e., a single
- It supports Unicode and filenames of up to 255
- It supports journaling by default, which provides protection
against power outages and hardware component failures and reduces the
need for repairs.
- Mac OS Extended volumes can optionally be formatted for case
sensitivity. This allows for different filenames that have the same
characters, but different case (e.g.,
Dogwould be different from
dog). This makes it more like formats used in other Unix operating systems.
Last modified on December 05, 2012.