ZFS

ZFS, short for zettabyte file system, is a file system and logical volume manager developed by Sun Microsystems. It is designed for high-performance, fault-tolerant, large-scale Unix-like systems.

ZFS history

ZFS was created at Sun in 2001 as a proprietary file system and was released as an open-source component of OpenSolaris in 2005. In 2010, when Oracle acquired Sun, ZFS reverted to closed-source, proprietary software.

In 2013, the development teams of the illumos, Linux, FreeBSD, and macOS operating systems collaborated to release a new open-source version of ZFS, OpenZFS.

ZFS features

ZFS features include:

• Maximum volume size of 256 trillion yottabytes.
• Maximum file size of 16 exbibytes.
• Unlimited number of files, maximum 2⁴⁸ per directory.
• POSIX (portable operating system interface for Unix) attributes and permissions, and NFSv4 ACLs.
• Support for forked file contents (extended attributes).
• Transparent file system compression and encryption.
• Support for RAID (redundant array of independent disks) levels 0, 1, 10, 5 (RAIDZ), 6 (RAIDZ2), and RAIDZ3.
• Copy-on-write and data deduplication.

Operating systems that support ZFS

The following operating systems completely or partially support ZFS:

• FreeBSD
• Illumos
• Linux
• macOS Server
• NetBSD
• OpenSolaris
• Solaris

Linux support

Due to licensing incompatibilities, ZFS support on Linux is largely restricted to user space, mounted as a FUSE (Filesystem in Userspace) file system. This restriction satisfies the ZFS license, at a performance cost. However, in 2016, Ubuntu 16.04 introduced a segregated development model that satisfies the ZFS license terms, and began including ZFS support as a kernel module.

Computer acronyms, Hierarchical file system, Operating System terms