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ZFS

Key facts

Filesystem.name: ZFS
Filesystem.variants: Oracle ZFS, OpenZFS
Filesystem.developer: Sun Microsystems originally, Oracle Corporation since 2010, OpenZFS since 2013
Filesystem.introduction_os: OpenSolaris
Filesystem.directory_struct: Extendible hashing
Filesystem.max_filename_size: 1023 ASCII characters (fewer for multibyte character standards such as Unicode)
Filesystem.max_volume_size: 256 trillion yobibytes (2128 bytes)
Filesystem.max_capacity: 256 UB (2128 bytes)
Filesystem.max_file_size: 16 exbibytes (264 bytes)
Filesystem.forks_streams: Yes (called "extended attributes", but they are full-fledged streams)
Filesystem.attributes: POSIX, extended attributes
Filesystem.file_system_permissions: Unix permissions, NFSv4 ACLs

via Wikipedia infobox

Article

39 sections

Contents

Overview
History
2004–2010: Development at Sun Microsystems
Since 2010: Development at Oracle, OpenZFS
Features
Summary
Data integrity
RAID
Avoidance of hardware RAID controllers
ZFS's approach: RAID-Z and mirroring
Resilvering and scrub (array syncing and integrity checking)
Capacity
Encryption
Read/write efficiency
Other features
Storage devices, spares, and quotas
Caching mechanisms: ARC, L2ARC, Transaction groups, ZIL, SLOG, Special VDEV
Special VDEV Class
Copy-on-write transactional model
Snapshots and clones
Sending and receiving snapshots
Dynamic striping
Variable block sizes
Lightweight filesystem creation
Adaptive endianness
Deduplication
Additional capabilities
Limitations
Data recovery
OpenZFS and ZFS
Commercial and open source products
Oracle Corporation, closed source, and forking (from 2010)
Version history
Operating system support
See also
Notes
References
Bibliography
External links

ZFS (previously Zettabyte File System) is a file system with volume management capabilities. It began as part of the Sun Microsystems Solaris operating system in 2001. Large parts of Solaris, including ZFS, were published under an open source license as OpenSolaris for around 5 years from 2005 before being placed under a closed source license when Oracle Corporation acquired Sun in 20092010. During 2005 to 2010, the open source version of ZFS was ported to Linux, Mac OS X (continued as MacZFS) and FreeBSD. In 2010, the illumos project forked a then-recent version of OpenSolaris, including ZFS, to continue its development as an open source project. In 2013, OpenZFS was founded to coordinate the development of open source ZFS. OpenZFS maintains and manages the core ZFS code, while organizations using ZFS maintain the specific code and validation processes required for ZFS to integrate within their systems. OpenZFS is widely used in Unix-like systems.

== Overview == The management of stored data generally involves two aspects: the physical volume management of one or more block storage devices (such as hard drives and SD cards), including their organization into logical block devices as VDEVs (ZFS Virtual Device) as seen by the operating system (often involving a volume manager, RAID controller, array manager, or suitable device driver); and the management of data and files that are stored on these logical block devices (a file system or other data storage). Example: A RAID array of 2 hard drives and an SSD caching disk is controlled by Intel's RST system, part of the chipset and firmware built into a desktop computer. The Windows user sees this as a single volume, containing an NTFS-formatted drive of their data, and NTFS is not necessarily aware of the manipulations that may be required (such as reading from/writing to the cache drive or rebuilding the RAID array if a disk fails). The management of the individual devices and their presentation as a single device is distinct from the management of the files held on that apparent device.