updated 11:00 am EDT, Mon October 8, 2007
Read-only ZFS for 10.5
Apple has confirmed that Mac OS X 10.5 (Leopard) will have limited support for ZFS (Zettabyte File System). "Apple will provide limited ZFS support in Leopard," said company spokesman Anuj Nayar. "It will only be available as a read-only option from the command line." In a Computerworld Apple said it was exploring ZFS as a file system option for high-end storage systems, noting the read-only status of the filesystem's inclusion in Leopard. Apple said ZFS will not be the default filesystem in Mac OS X 10.5, and that it will incorporate its well-known HFS+ as the default file system -- which falls in line with industry skeptics who said using ZFS as the default file system for Leopard made no sense.
Despite this claim, however, AppleInsider cites Mac OS X developers who have received the latest ZFS preview as a strong sign that the Cupertino-based company plans to increase adoption of ZFS. Those sources also believe that Apple is considering ZFS as a potential successor to its current HFS+ file system as the default underlying structure for Mac OS X. That belief coincides with a statement made by Sun CEO Jonathan Schwartz in June, when the executive claimed Mac OS X 10.5 Leopard would use ZFS rather than HFS. Schwartz revoked that statement shortly after issuing it, however, leaving industry watchers wondering whether Sun's chief prematurely announced future development plans.
ZFS is a filesystem developed by Sun that is 128-bit, meaning it offers 16 billion billion times the capacity of 32- or 64-bit systems -- virtually unlimited by today's standards. ZFS also offers increased performance because it uses a transactional object model rather than more traditional I/O mechanisms.
Another purported benefit of ZFS is the elimination of various administration and maintenance routines required by other filesystems. For instance, the fsck command never needs to run, even if the system is shut down in an unclean fashion -- the creators claim that ZFS has never lost data integrity or leaked a single block after thousands of forced violent crashes.