The OneFS File System is a parallel distributed networked file system designed by

Isilon Systems Dell EMC Isilon is a scale out network-attached storage platform offered by Dell EMC for high-volume storage, backup and archiving of unstructured data. It provides a cluster-based storage array based on industry standard hardware, and is scala ...

and is the basis for the ''Isilon Scale-out Storage Platform''. The OneFS file system is controlled and managed by the OneFS Operating System, a

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...

variant.

On-disk Structure

All data structures in the OneFS file system maintain their own protection information. This means in the same filesystem, one file may be protected at +1 (basic parity protection) while another may be protected at +4 (resilient to four failures) while yet another file may be protected at 2x (

mirror A mirror or looking glass is an object that reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the direction of the im ...

ing); this feature is referred to as FlexProtect. FlexProtect is also responsible for automatically rebuilding the data in the event of a failure. The protection levels available are based on the number of nodes in the cluster and follow the Reed Solomon Algorithm. Blocks for an individual file are spread across the nodes. This allows entire nodes to fail without losing access to any data. File

metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...

, directories, snapshot structures, quotas structures, and a logical

inode The inode (index node) is a data structure in a Unix-style file system that describes a file-system object such as a file or a directory. Each inode stores the attributes and disk block locations of the object's data. File-system object attribut ...

mapping structure are all based on mirrored

B+ tree A B+ tree is an m-ary tree with a variable but often large number of children per node. A B+ tree consists of a root, internal nodes and leaves. The root may be either a leaf or a node with two or more children. A B+ tree can be viewed as a ...

s. Block addresses are generalized 64-bit pointers that reference (node, drive, blknum)

tuple In mathematics, a tuple is a finite ordered list (sequence) of elements. An -tuple is a sequence (or ordered list) of elements, where is a non-negative integer. There is only one 0-tuple, referred to as ''the empty tuple''. An -tuple is defi ...

s. The native block size is 8192 bytes; inodes are 512 bytes on disk (for disks with 512 byte sectors) or 8KB (for disks with 4KB sectors). One distinctive characteristic of OneFS is that metadata is spread throughout the nodes in a homogeneous fashion. There are no dedicated metadata servers. The only piece of metadata that is replicated on every node is the address list of root btree blocks of the inode mapping structure. Everything else can be found from that starting point, following the generalized 64-bit pointers.

Clustering

The collection of computer hosts that comprise a OneFS System is referred to as a "''cluster''". A computer host that is a member of a OneFS cluster is referred to as a "''node''" (plural "''nodes''"). The nodes that comprise a OneFS System must be connected by a high performance, low-latency back-end network for optimal performance. OneFS 1.0-3.0 used Gigabit Ethernet as that back-end network. Starting with OneFS 3.5, Isilon offered

InfiniBand InfiniBand (IB) is a computer networking communications standard used in high-performance computing that features very high throughput and very low latency. It is used for data interconnect both among and within computers. InfiniBand is also use ...

models. From about 2007 until mid-2018, all nodes sold utilized an InfiniBand back-end. Starting with OneFS 8.1.0 and Gen6 models, Isilon again offers Ethernet back-end network (10, 25, 40, or 100 Gigabit). Data, metadata, locking, transaction, group management, allocation, and event traffic are communicated using an RPC mechanism traveling over the back-end network of the OneFS cluster. All data and metadata transfers are

zero-copy "Zero-copy" describes computer operations in which the CPU does not perform the task of copying data from one memory area to another or in which unnecessary data copies are avoided. This is frequently used to save CPU cycles and memory bandwi ...

. All modification operations to on-disk structures are transactional and journaled.

Protocols

OneFS supports accessing stored files using common computer network protocols including NFS, CIFS/SMB, FTP,

HTTP The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide We ...

, and

HDFS Apache Hadoop () is a collection of open-source software utilities that facilitates using a network of many computers to solve problems involving massive amounts of data and computation. It provides a software framework for distributed storage an ...

. It can utilize non-local authentication such as

Active Directory Active Directory (AD) is a directory service developed by Microsoft for Windows domain networks. It is included in most Windows Server operating systems as a set of processes and services. Initially, Active Directory was used only for centralize ...

LDAP The Lightweight Directory Access Protocol (LDAP ) is an open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed directory information services over an Internet Protocol (IP) network. Directory servi ...

, and NIS. It is capable of interfacing with external backup devices and applications that use NDMP protocol.

OneFS Operating System

The OneFS File System is a proprietary file system that can only be managed and controlled by the FreeBSD-derived OneFS Operating System. zsh is the default login shell of the OneFS Operating System. OneFS presents a specialized command set to administer the OneFS File System. Most specialized shell programs start with letters ''isi''. Notable exceptions are the Isilon extensions to the FreeBSD ls and chmod programs.

Versions

* 1.0 "Bell," 2.0 "Jalapeno," 3.0 "Serrano," 3.5 "Tabasco" * 4.0 "Poblano," 4.1 "Anaheim," 4.5 "Thai," 4.6 "Ancho" * 4.7 "Chiltepin" ** 4.7.1 to .11 * 5.0 "Jamaican" ** 5.0.0 to .8 * 5.5 "Scotch Bonnet" (based on FreeBSD 6.1)Determined by the __FreeBSD_version

definition A definition is a statement of the meaning of a term (a word, phrase, or other set of symbols). Definitions can be classified into two large categories: intensional definitions (which try to give the sense of a term), and extensional definiti ...

in /usr/include/sys/param.h. See ''FreeBSD Porter's Handbook'' for more information. ** 5.5.1 to .2 ** 5.5.3 - OS updates with rolling reboots of individual nodes. ** 5.5.4 - Adds

iSCSI Internet Small Computer Systems Interface or iSCSI ( ) is an Internet Protocol-based storage networking standard for linking data storage facilities. iSCSI provides block-level access to storage devices by carrying SCSI commands over a TCP/IP ...

** 5.5.5 to .7 * 6.0 "Habanero" - Up to 10.4 PB in a single file system ** 6.0.1 to .4 * 6.5 "Chopu" (based on FreeBSD 7.3) ** 6.5.1 to .5 * 7.0 "Mavericks" - released November 2012; (based on FreeBSD 7.4-STABLE) ** 7.0.1 to .2 * 7.1 "Waikiki" - released October 2013 ** 7.1.1 "Jaws" - released July 2014 * 7.2 "Moby" - released November 2014 ** 7.2.0, 7.2.1 * 8.0 "Riptide" (based on FreeBSD 10) - released February 2016 -

deprecated ** 8.0.1 "Halfpipe" - released October 2016 * 8.1 "Freight Trains" - released June 2017 ** 8.1.1 "Niijima" - released January 2018 ** 8.1.2 "Kanagawa" - Released August 2018 ** 8.1.3 "Seismic" - Released January 2019 * 8.2.0 "Pipeline" (based on FreeBSD 11) - Released May 2019 ** 8.2.1 "Acela" - Released September 2019 ** 8.2.2 "Beachcomber" - Released January 2020 * 9.0.0.0 "Cascades" - Released June 2020 ** 9.1.0.0 - Released October 2020 ** 9.2 - Released April 2021 ** 9.3 - Released October 2021 ** 9.4 - Released April 2022

References

External links

* {{File systems Distributed file systems