C
CIFS
An obsolete name for SMB version 1.0 (Common Internet File System)
Consistent Hash Tables
Consistent hash tables are a special form of hash tables that minimize the amount of data that must be moved to expand the hash table.
D
DASE
The VAST DASE (Disaggregated Shared Everything Architecture) disaggregates (separates) the storage media from the CPUs that manage that media and provide storage services. This disaggregated storage, including all the system metadata, is shared by all the VAST Servers in the cluster. DASE allows users to scale the capacity of a VAST Cluster independently from the compute resources of the cluster, adding enclosures for capacity and servers for performance.
DataStore
The VAST DataStore is a single storage system that is fast enough for primary storage, scalable enough for huge datasets and affordable enough to use for the full range of a customer's data, thus eliminating the tyranny of tiers. It is one of the many features within the VAST Data Platform.
E
Enclosure Fabric Module
An Enclosure Fabric Module, as known as a DNode, connects the Storage Class Memory and QLC SSDs in the enclosure to the NVMe Fabric in each VAST Enclosure. Each Fabric Module provides multiple fabric connections (100Gbps Ethernet or Infiniband) and a PCIe switch complex that connects the fabric to all the SSDs in the enclosure. In the event of Fabric Module failure, the SSDs remain connected to the fabric via the surviving Fabric Module.
F
Foresight
Predictive Placement, also known as Foresight, is the process of predicting the expected lifetime of a piece of data and storing data with similar life-expectancies together to minimize garbage collection and the write amplification it creates.
G
Gemini
VAST’s go-to-market model where users buy their storage hardware at cost from VAST’s manufacturing partner and a capacity-based subscription from VAST that includes both a license to run VAST’s software and support for both the software and hardware including parts replacement.
H
HPC
The VAST Data Platform accelerates HPC by delivering the performance and scale of parallel file systems with the simplicity of NAS, all at archive economics. Powered by VAST’s DASE architecture, our customers build scale-out systems delivering TB/s and millions of IOPS of performance without the rigidity and overhead of legacy architectures.
Hyperscale Flash
A class of SSDs designed to deliver the capacity and reliability required by hyperscale storage systems without the additional cost of the “enterprise” features required by legacy storage architectures. Hyperscale SSDs: • Use high bit/cell flash (4 bit/cell QLC and/or 5 bit/cell PLC) • Have a single NVMe port vs premium priced dual port enterprise drives • Write directly to high bit/cell flash w/o DRAM or SLC caches • Which eliminates the need for power failure protection circuitry, and batteries or ultra-capacitors to power same
L
Locally Decodable Erasure Code
Locally Decodable erasure codes are a class of forward error-correcting codes that can reconstruct erased data, like the data on a failed drive, using only a small fraction of the surviving data strips. VAST clusters using N+4 coding can reconstruct the data from a lost drive using just 1/4th the data, and therefore 1/4th the I/Os, of a conventional erasure coding scheme.
N
NVMe (Non-Volatile Memory Express)
NVMe is a new protocol designed specifically to provide systems access to non-volatile memory devices like SSDs. NVMe has much lower overhead, and allows much more parallel I/O than the older SCSI protocol.
NVMe-oF (NVM-e Over Fabrics)
NVMe-oF (Non Volatile Memory express over Fabrics) extends the NVMe protocol to allow systems to access NVMe SSDs over fabric networks like Ethernet and/or Infiniband as well as PCIe connections.
O
Operational Lock
Operational Lock, or Op-Lock, is what SMB Clients use to indicate byte ranges in a file they are caching without actually preventing other users from writing. When another user overwrites data, a client has op-locked, the server sends a notification invalidating the cached data.
P
Predictive Placement
Predictive Placement, also known as Foresight, is the process of predicting the expected lifetime of a piece of data and storing data with similar life-expectancies together to minimize garbage collection and the write amplification it creates.
Q
Quad Server (Module) Chassis
A Quad Server (Module) Chassis, also known a CBox, is a 2U high-density chassis holding four dual-Xeon servers running VAST Server Containers.
R
Representational State Transfer
Representational State Transfer, or REST, is a set of design standards for communications between systems and applications. REST defines communications that are stateless, use self-describing data formats like JSON or XML, and transfer data via HTTP or HTTPS. An API that follows the REST strictures is said to be RESTful.
S
Scale-Out
Scale-Out storage systems allow users to grow a system by adding compute power along with media in the form of HDDs and SSDs. Scale-Out storage systems can usually scale larger than systems based on the older scale-up architecture.
Scale-Up
A storage system architecture that allows storage systems to scale in capacity by adding drives (flash or spinning) to one or two controllers that provide a fixed amount of processing power. Compare to Scale-out.
SMB
Server Message Block is the file protocol developed by Microsoft. The now obsolete and deprecated version 1.0 was known as CIFS. Primary file protocol for Windows and OS X.
SMB Leases
A more advanced form of Op-Lock.
Snaptime
The snaptime is a global system counter that dates back to the installation of a VAST cluster and is advanced synchronously across all the VAST Servers (CNodes) in a cluster. Metadata updates are timestamped with current snaptime as they’re written.
Storage Class Memory
Storage Class Memory is a new non-volatile memory technology that has much lower latency and much higher endurance than NAND Flash. The VAST Data Platform uses Storage Class Memory SSDs to store system and element store metadata as well as a write buffer.
U
Uniform Resource Identifier
A Uniform Resource Identifier, also known as a URL or Uniform Resource Locator, specifies both the location of a resource (EG:TopModel.com/HeidiKlum/red_carpet_325.jpg) and the protocol used to access it (EG:https://).
V
VAST Cluster
A VAST Cluster is the set of VAST Servers (CNodes) and VAST Enclosures (DBoxes) that make up a single management domain and namespace.
VAST Element Store
The VAST Element Store defines how VAST’s data platform store files and objects and the metadata that describes them. The Element Store is neither a traditional file system nor an object store, abstracting both to create an abstraction that serves both the hierarchical presentation of a file system and the flat presentation of an object store. This abstraction allows users to access the same element as a file over NFS with one application and as an S3 object when using more modern “cloud-native” applications.
VAST Enclosure
A VAST Enclosure, also known as a DBox, is a highly-available NVMe over Fabrics JBOF (Just a Bunch of Flash) making the Storage Class Memory and QLC Flash SSDs the enclosure contains available to all the VAST Servers (CNodes) in a cluster.
VAST Insight
VAST Insight is the analytics platform that collects and analyzes data from VAST Clusters in the field. VAST Insight allows VAST to proactively identify degraded devices, like SSDs, so they can be replaced before they fail and provides insight to system administrators on the health of their systems.
VAST Probe
The VAST Probe is a software application that scans a file repository and reports how much the data in the repository would reduce using VAST’s Global Similarity Reduction. The VAST Probe is usually supplied as a docker container the user organization can host.
VAST Server
Stateless VAST Servers, also known as CNodes, which run in VAST Server Containers, provide all the storage protocol and management services in a VAST Cluster. Each VAST Server can directly access all the Storage Class Memory and QLC SSDs in all the VAST Enclosures in the VAST Cluster.
VAST Server Container
A VAST Server Container is a Docker container holding a logical VAST Server.
VAST Server Host
A VAST Server Host is a physical server running a VAST Server Container.
VAST Server Module
A VAST Server Module is one of the four dual-Xeon servers in a Quad Server Chassis. The VAST Server Module is a field replaceable unit (FRU).
VAST View
VAST views are a protocol-independent version of the NFS Exports and SMB shares. A View can present a folder as either or both. View policies control if NFS (POSIX) or SMB ACLs will apply.
VASTsnap
A VASTsnap is VAST’s zero-write Snapshot technology.
Z
Zero Compromise Guarantee
Gemini is the data platform business model reinvented for savings, simplicity and choice. With Gemini, customers purchase managed software on hardware that is purchased directly from manufacturers at cost.