A
Solaris
file system that uses
storage pools to manage physical storage. The
ZFS pooled storage model eliminates the concept of
volumes and the associated
problems of partitions, provisioning and stranded storage by enabling thousands
of
file systems to draw from a common storage pool, using only as much space as
it actually needs. ZFS also uses RAID-Z, a data replication model that is
similar to RAID-5 but uses variable
stripe width to eliminate the
RAID-5 write
hole—that is stripe corruption due to loss of power between data and parity
updates. All RAID-Z writes are full-stripe writes. There's no read-modify-write
tax, no write hole, and no need for NVRAM in hardware.
According to the FAQ posted on OpenSolaris.org, originally, ZFS was an
acronym for "Zettabyte File System." The largest
SI prefix that the developers
liked was 'zetta', and since ZFS is a 128-bit file system, the name was a
reference to the fact that ZFS can store 256 quadrillion
zettabytes (where each
ZB is 270 bytes). Over time, ZFS gained a lot more features besides 128-bit
capacity, such as rock-solid data integrity, easy administration, and a
simplified model for managing your data.
ZFS is open-source software that is licensed under the Common Development and
Distribution License (CDDL).
See also
ZFS Frequently Asked Questions on OpenSolaris.org.
