With OS 10.5, Apple will use the Sun file system, ZFS (Zettabyte File System).
Sun’s Jonathan Schwartz let that slip on Wednesday during a Sun presentation. I say “let it slip” because Apple doesn’t like advance announcements. Steve Jobs will confirm that file system during the Apple Worldwide Developers Conference on June 11.
Here is a link all about ZFS.
It looks interesting. From their web site, “ZFS presents a pooled storage model that completely eliminates the concept of volumes and the associated problems of partitions, provisioning, wasted bandwidth and stranded storage. Thousands of filesystems can draw from a common storage pool, each one consuming only as much space as it actually needs. The combined I/O bandwidth of all devices in the pool is available to all filesystems at all times.
All operations are copy-on-write transactions, so the on-disk state is always valid. There is no need to fsck(1M) a ZFS filesystem, ever. Every block is checksummed to prevent silent data corruption, and the data is self-healing in replicated (mirrored or RAID) configurations. If one copy is damaged, ZFS will detect it and use another copy to repair it.”