| Developer(s) | Isilon Systems |
|---|---|
| Full name | OneFS |
| Introduced | 2003; 22 years ago (2003) with OneFS 1.0 -- based onFreeBSD |
| 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 |
| Maxno. of files | Cluster size dependent |
| Max filename length | 255bytes |
| 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 andAlternate Data Streams) |
| File system permissions | Yes (POSIX permissions andNTFSACLs) |
| 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 |
TheOneFS File System is aparallel distributed networked file system designed byIsilon Systems and is the basis for theIsilon Scale-out Storage Platform.[3] The OneFS file system is controlled and managed by theOneFS Operating System, aFreeBSD 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 theReed Solomon Algorithm. Blocks for an individual file are spread across the nodes. This allows entire nodes to fail without losing access to any data. Filemetadata, directories,snapshot structures,quotas structures, and a logicalinode mapping structure are all based on mirroredB+ trees. Block addresses are generalized 64-bitpointers 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 offeredInfiniBand 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 anRPC mechanism traveling over the back-end network of the OneFS cluster. All data and metadata transfers arezero-copy. All modification operations to on-disk structures are transactional andjournaled.
OneFS supports accessing stored files using common computer network protocols includingNFS,CIFS/SMB,FTP,HTTP, andHDFS.[3] It can utilize non-local authentication such asActive Directory,LDAP, andNIS. It is capable of interfacing with external backup devices and applications that useNDMP protocol.[3]
The OneFS File System is a proprietary file system that can only be managed and controlled by theFreeBSD-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 lettersisi. Notable exceptions are the Isilon extensions to the FreeBSDls andchmod programs.[7]
__FreeBSD_versiondefinition in/usr/include/sys/param.h. SeeFreeBSD Porter's Handbook for more information.