Apple's HFS+ file system will be replaced by Sun's open source ZFS, Sun chief Jonathan Schwartz revealed on stage ahead of Apple's WWDC developer conference.
On stage in Washington DC, Schwartz revealed that ZFS will replace Apple's long-used HFS+ in Mac OS X 10.5, known as "Leopard," when the new operating system ships this autumn.
"This week, you'll see that Apple is announcing at their Worldwide Developers Conference that ZFS has become the file system in Mac OS X," said Schwartz.
ZFS, designed by Sun for its Solaris OS but licensed as open-source, is a 128-bit file storage system that features, among other things, "pooled storage," which means that users simply plug in additional drives to add space, without worrying about such traditional storage parameters as volumes or partitions.
"[ZFS] eliminates volume management, it has extremely high performance.... It permits the failure of disk drives," said Schwartz during a presentation focused on Sun's new blade servers. Apple's operating system currently relies on HFS+ (Hierarchical File System Plus), a 1998 extension of 1985's HFS.
ZFS was touted by many as a possible successor to HFS+ last summer, immediately after Apple's CEO Steve Jobs first showed off the new backup feature planned to debut in Leopard.
In the intervening months, however, the ZFS-Time Machine connections were downplayed or dismissed by most observers. Even today, after Schwartz talked up ZFS, bloggers seemed skeptical about the file system's place in Leopard.
"I'll stick to my prediction that Apple, as with HFS+, will put ZFS on OS X Server first before bringing it out later for the great unwashed," said Robin Harris on his StorageMojo blog.
Most objections centred around the short time between now and Leopard's October release, and the implications of such a major makeover. Others at Sun, however, seemed to confirm that ZFS would be the default file system.
"Jonathan noted that Apple will announce this week that the ZFS file system from OpenSolaris will become Apple's new default file system," said Marc Hamilton, Sun's director of technology for global education and research, on his company blog.
"So how does that help Sun? It is pretty simple, now every Apple developer will know ZFS and how to use it on our SunFire x4500 storage server and other Sun products." A Sun spokeswoman would not confirm or deny that ZFS would be Mac OS X 10.5's default file system.
"I can't tell you anything more than what Jonathan [Schwartz] said today," she said.
Apple does not comment on unannounced products or product features. Schwartz may have unwittingly stolen some of Jobs' thunder for next week, since Apple watchers expect the Apple CEO to tout Leopard - especially features previously not made public - during his WWDC keynote next Monday.