Developer(s) | Isilon Systems |
---|---|
Full name | OneFS |
Introduced | 2003FreeBSD | with OneFS 1.0 -- based on
Structures | |
Directory contents | B+ trees |
File allocation | B+ trees |
Limits | |
Max volume size | 66PB+ (144+ nodes at 470TB+ each); [1] 65535 nodes theoretical limit |
Max file size | 16TB |
Max no. of files | Cluster size dependent |
Max filename length | 255 bytes |
Max directory depth | 509 (suggested, to fit within PATH_MAX of 1023) [1] |
Allowed filename characters | Many (UTF-8, EUC-JP, CP932, CP1252, ISO-8859-*, EUC-KR, CP949). Encoding is per-directory entry, not per-filesystem. So multiple encodings may be used in a single volume. UTF-8 is encouraged as normative. NUL and / are not allowed in individual directory entries in any encoding. |
Features | |
Dates recorded | Create time, rename time, mtime, ctime, atime |
Date range | 1970 to 2038 |
Date resolution | Nanosecond |
Forks | Yes (extended attributes and Alternate Data Streams) |
File system permissions | Yes (POSIX permissions and NTFS ACLs) |
Transparent compression | Yes [2] |
Transparent encryption | Integrated with Self-encrypting Drives for encryption of "data at rest" [3] |
Data deduplication | Offline only |
Copy-on-write | Yes (for snapshots) |
Other | |
Supported operating systems | OneFS |
The OneFS File System is a parallel distributed networked file system designed by Isilon Systems and is the basis for the Isilon Scale-out Storage Platform. [3] The OneFS file system is controlled and managed by the OneFS Operating System, a FreeBSD variant. [3]
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 (mirroring); this feature is referred to as FlexProtect. [4] 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, directories, snapshot structures, quotas structures, and a logical inode mapping structure are all based on mirrored B+ trees. Block addresses are generalized 64-bit pointers that reference (node, drive, blknum) tuples. 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.
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 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). [5]
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. All modification operations to on-disk structures are transactional and journaled.
OneFS supports accessing stored files using common computer network protocols including NFS, CIFS/SMB, FTP, HTTP, and HDFS. [3] It can utilize non-local authentication such as Active Directory, LDAP, and NIS. It is capable of interfacing with external backup devices and applications that use NDMP protocol. [3]
The OneFS File System is a proprietary file system that can only be managed and controlled by the FreeBSD-derived OneFS Operating System. [3]
zsh is the default login shell of the OneFS Operating System. OneFS presents a specialized command set to administer the OneFS File System. [6] Most specialized shell programs start with letters isi. Notable exceptions are the Isilon extensions to the FreeBSD ls
and chmod
programs. [7]
XFS is a high-performance 64-bit journaling file system created by Silicon Graphics, Inc (SGI) in 1993. It was the default file system in SGI's IRIX operating system starting with its version 5.3. XFS was ported to the Linux kernel in 2001; as of June 2014, XFS is supported by most Linux distributions; Red Hat Enterprise Linux uses it as its default file system.
ext2, or second extended file system, is a file system for the Linux kernel. It was initially designed by French software developer Rémy Card as a replacement for the extended file system (ext). Having been designed according to the same principles as the Berkeley Fast File System from BSD, it was the first commercial-grade filesystem for Linux.
Journaled File System (JFS) is a 64-bit journaling file system created by IBM. There are versions for AIX, OS/2, eComStation, ArcaOS and Linux operating systems. The latter is available as free software under the terms of the GNU General Public License (GPL). HP-UX has another, different filesystem named JFS that is actually an OEM version of Veritas Software's VxFS.
The Unix file system (UFS) is a family of file systems supported by many Unix and Unix-like operating systems. It is a distant descendant of the original filesystem used by Version 7 Unix.
The inode 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 attributes may include metadata, as well as owner and permission data.
In computing, the Global File System 2 (GFS2) is a shared-disk file system for Linux computer clusters. GFS2 allows all members of a cluster to have direct concurrent access to the same shared block storage, in contrast to distributed file systems which distribute data throughout the cluster. GFS2 can also be used as a local file system on a single computer.
The Write Anywhere File Layout (WAFL) is a proprietary file system that supports large, high-performance RAID arrays, quick restarts without lengthy consistency checks in the event of a crash or power failure, and growing the filesystems size quickly. It was designed by NetApp for use in its storage appliances like NetApp FAS, AFF, Cloud Volumes ONTAP and ONTAP Select.
The VERITAS File System is an extent-based file system. It was originally developed by VERITAS Software. Through an OEM agreement, VxFS is used as the primary filesystem of the HP-UX operating system. With on-line defragmentation and resize support turned on via license, it is known as OnlineJFS. It is also supported on AIX, Linux, Solaris, OpenSolaris, SINIX/Reliant UNIX, UnixWare and SCO OpenServer. VxFS was originally developed for AT&T's Unix System Laboratories. VxFS is packaged as a part of the Veritas Storage Foundation.
Lustre is a type of parallel distributed file system, generally used for large-scale cluster computing. The name Lustre is a portmanteau word derived from Linux and cluster. Lustre file system software is available under the GNU General Public License and provides high performance file systems for computer clusters ranging in size from small workgroup clusters to large-scale, multi-site systems. Since June 2005, Lustre has consistently been used by at least half of the top ten, and more than 60 of the top 100 fastest supercomputers in the world, including the world's No. 1 ranked TOP500 supercomputer in November 2022, Frontier, as well as previous top supercomputers such as Fugaku, Titan and Sequoia.
Journalling Flash File System version 2 or JFFS2 is a log-structured file system for use with flash memory devices. It is the successor to JFFS. JFFS2 has been included into the Linux kernel since September 23, 2001, when it was merged into the Linux kernel mainline as part of the kernel version 2.4.10 release. JFFS2 is also available for a few bootloaders, like Das U-Boot, Open Firmware, the eCos RTOS, the RTEMS RTOS, and the RedBoot. Most prominent usage of the JFFS2 comes from OpenWrt.
The following tables compare general and technical information for a number of file 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 scalable to 50 petabytes in a single filesystem using its FreeBSD-derived OneFS file system.
A clustered file system (CFS) is a file system which is shared by being simultaneously mounted on multiple servers. There are several approaches to clustering, most of which do not employ a clustered file system. Clustered file systems can provide features like location-independent addressing and redundancy which improve reliability or reduce the complexity of the other parts of the cluster. Parallel file systems are a type of clustered file system that spread data across multiple storage nodes, usually for redundancy or performance.
Btrfs is a computer storage format that combines a file system based on the copy-on-write (COW) principle with a logical volume manager, developed together. It was created by Chris Mason in 2007 for use in Linux, and since November 2013, the file system's on-disk format has been declared stable in the Linux kernel.
Ceph is a free and open-source software-defined storage platform that provides object storage, block storage, and file storage built on a common distributed cluster foundation. Ceph provides distributed operation without a single point of failure and scalability to the exabyte level. Since version 12 (Luminous), Ceph does not rely on any other conventional filesystem and directly manages HDDs and SSDs with its own storage backend BlueStore and can expose a POSIX filesystem.
HAMMER is a high-availability 64-bit file system developed by Matthew Dillon for DragonFly BSD using B+ trees. Its major features include infinite NFS-exportable snapshots, master–multislave operation, configurable history retention, fsckless-mount, and checksums to deal with data corruption. HAMMER also supports data block deduplication, meaning that identical data blocks will be stored only once on a file system. A successor, HAMMER2, was announced in 2011 and became the default in Dragonfly 5.2.
Dell Technologies PowerFlex, is a commercial software-defined storage product from Dell Technologies that creates a server-based storage area network (SAN) from local server storage using x86 servers. It converts this direct-attached storage into shared block storage that runs over an IP-based network.
__FreeBSD_version
definition in /usr/include/sys/param.h
. See FreeBSD Porter's Handbook for more information.