HFS+
HFS+, or Hierarchical File System Plus, is the file system designed by Apple Computer[1] to supersede HFS. First introduced with Mac OS 8.1, one of the biggest differences was the lower allocation block size of 4kb, thereby increasing performance and lowering fragmentation [2].
There are structurally many differences between HFS and HFS+, which are listed below[3]:
|
Feature |
HFS |
HFS Plus |
Benefit/Comment |
|
User visible name |
Mac OS Standard |
Mac OS Extended | |
|
Number of allocation blocks |
16 bits worth |
32 bits worth |
Radical decrease in disk space used on large volumes, and a larger number of files per volume. |
|
Long file names |
31 characters |
255 characters |
Obvious user benefit; also improves cross-platform compatibility |
|
File name encoding |
MacRoman |
Unicode |
Allows for international-friendly file names, including mixed script names |
|
File/folder attributes |
Support for fixed size attributes (FileInfo and ExtendedFileInfo) |
Allows for future meta-data extensions |
Future systems may use metadata for a richer Finder experience |
|
OS startup support |
System Folder ID |
Also supports a dedicated startup file |
May help non-Mac OS systems to boot from HFS Plus volumes |
|
catalog node size |
512 bytes |
4 KB |
Maintains efficiency in the face of the other changes. (This larger catalog node size is due to the much longer file names [512 bytes as opposed to 32 bytes], and larger catalog records (because of more/larger fields)). |
|
Maximum file size |
231 bytes |
263 bytes |
Obvious user benefit, especially for multimedia content creators. |
An HFS+ volume contains five special files that are necessary to the file system:
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