Revision as of 20:35, 5 October 2010

Question

What requirements distinguish the Zettabyte File System (ZFS) from traditional file systems? How are those requirements realized in ZFS, and how do other operating systems address those same requirements? (Please discuss legacy, current, and in-development systems.)

Answer

ZFS was developed by Sun Microsystems (now owned by Oracle) as a server class file systems. This differs from most file systems which were developed as desktop file systems that could be used by servers. With the server being the target for the file system particular attention was paid to data integrity, size and speed.

One of the most significant ways in which the ZFS differs from traditional file systems is the level of abstraction. While a traditional file system abstracts away the physical properties of the media upon which it lies i.e. hard disk, flash drive, CD-ROM, etc. ZFS abstracts away if the file system lives one or many different pieces of hardware or media. Examples include a single hard drive, an array of hardrives, a number of hard drives on non co-located systems.

One of the mechanisms that allows this abstraction is that the volume manager which is normally a program separate from the file system in traditional file systems is moved into ZFS.

ZFS is a 128-bit operating system allowing.

Another major difference between ZFS and traditional filesystems is data integrity.

- Checksums - self monitoring using mirroring/copy-on-write. - transactional based file IO