Mac OS X 10.6 Server Admin: About Mac OS Extended (Journaled, Case-Sensitive) aka HFSX

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About Mac OS Extended (Journaled, Case-Sensitive) aka HFSX

HFSX is an extension to HFS Plus and allows volumes to have case-sensitive file and directory names. Case-sensitive names means that you can have two objects whose names differ only by the case of the letters in the same directory at the same time. For example, you could have Bob, BOB, and bob in the same directory as uniquely named files.

A case-sensitive volume is supported as a start volume format. An HFSX file system for Mac OS X Server must be specifically selected when erasing a volume and preparing a disk before initial installation.

If you are planning to use NFS, you should use case-sensitive HFSX.

An HFSX volume can be case sensitive or case insensitive. Case sensitivity (or lack thereof) is global to the volume. The setting applies to all file and directory names on the volume. To determine whether an HFSX volume is case-sensitive, use Disk Utility to examine the format of the disk.

Note:  Do not assume that an HFSX volume is case sensitive. Always use Disk Utility to determine case sensitivity or case insensitivity. Additionally, don’t assume your third-party software solutions work correctly with case sensitivity.
Important:  Case-sensitive names do not ignore Unicode ignorable characters. This means that a single directory can have several names that are considered equivalent using Unicode comparison rules, but they are considered distinct on a case-sensitive HFSX volume.
Last Modified: Aug 6, 2013
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