Glossary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Accesser
Machine hosting the iSCSI target.
Account
A formal contractual relationship established to provide specific goods and/or services - in this case, data storage. An account can occur at many levels, e.g. a Dispersed Storage Network (dsNet) owner may have an account with Cleversafe; a user may have an account to use grid storage; a user may have an account with a dsNet owner. In Cleversafe usage, the term Account usually implies one user of data storage and one billable entity. See also dsNet Account in this glossary.
Appliance
Hardware and software combined for one purpose that are sold and delivered as one unit.
Application
At Cleversafe, usually used to mean an end-user application that might make use of the dsNet as it's storage device. One way an application could talk to the dsNet software is to use the existing client file system, which accesses the dsNet through a special device driver.
B
Block Layer
An architectural layer of the dsNet access software that exposes a vault on the dsNet as an array of blocks, similar to traditional block devices.
C
Client File System
The file system on the source computer.
Connector
A connector utilizes dsNet Services through the API, and provides services to a particular market. Typically a connector is developed for a specific application.
Credentials
A set of data used to authenticate to a Slicestor with an account.
D
Data
The data portion of a Datasource, what the user thinks of as his/her data.
Data Coding Stack
The list of transformations a datasource will undergo before storage on the dsNet.
Datasource
A source of data, the unit of data which can or will be stored on the Cleversafe dsNet. The most common sources of data are files, but a datasource could also be a directory, a block, or other discrete unit of data. A Datasource includes its Data and its Metadata.
Datasource Container
A datasource that references other datasources. The most common datasource container is a filesystem directory entry.
Device Access Layer
An architectural layer of the dsNet access software which exposes a vault as a block device accessible through SCSI-based protocols.
Dispersal
The creation of slices from a datasource using an IDA and storing them on (usually separated) Slicestors.
dsNet
Dispersed Storage Network. A connected logical or physical grouping of data storage devices, configured to be managed as one unit for storage of data. A dsNet usually implies dispersed storage media, although it can also be configured locally. The dsNet concept also includes the software necessary to manage the dsNet and disperse data onto the dsNet for storage.
dsNet Access Device
In the Cleversafe dsNet system, a machine that mediates between the client and the Slicestors. It contains the iSCSI target and performs the transformation and slicing of the client's data.
dsNet Account
A user account for storage of data on a dsNet. The dsNet Account is identified by a UUID, is the account known by to the dsNet, and can eventually be moved to a different dsNet if desired by the user.
dsNet Layer
An architectural layer of the Cleversafe dsNet access software that manages the incoming data on the dispersed storage network, including the transformations to slices.
dsNet Manager
An application for managing the Cleversafe dsNet.
dsNet Owner
A company or individual who owns (and manages) a Cleversafe dsNet. The dsNet owner can have its own customers which pay for use of the dsNet storage, and/or use the dsNet for its own storage needs.
dsNet Width
The width of the dsNet refers to the total number of Slicestors.
E
Expansion Factor
Amount of data increase from original data size after it runs through an IDA. Expressed as a multiplier of the original data, and is calculated by the sum of all the slices that are dispersed for the original data divided by the size of the original data.
F
No termsG
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I
Integrity codec
A pluggable module of the Cleversafe software that calculates an integrity checksum (hash, signature, etc.) for a slice or a datasource when it is written, and recalculates and compares when it is read.
IQN
The iSCSI Qualified Name (IQN) for each target node is a combination of the organizational naming authority and the universally unique identifier (UUID) of the block device vault it represents. The iSCSI target daemon constructs iSCSI names according to RFC 3720 and RFC 3721.
J
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K
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P
Protocol layer
An architectural layer of the Cleversafe dsNet access Software that implements the coding and decoding of grid protocol messages between the dsNet access device and the Slicestors.
Q
No terms
R
Read Threshold
The minimum number of Slicestors required for reading a datasource from the Cleversafe dsNet.
Rebuilder
A group of modules in the Cleversafe module dedicated to finding and fixing missing or corrupted Slices on stored data.
Request Handler Layer
An architectural layer in the Cleversafe dsNet access software that routes requests from the protocol layer.
S
SCSI Layer
An architectural layer of the dsNet access software that interprets SCSI Command Descriptor Blocks and translates requests to the next layer.
Slice
A slice is a dispersed piece of encoded data. Slices are created from an original datasource, and can be used to recreate the original datasource.
Slicestor
One of potentially several nodes in the Cleversafe Dispersed Storage Network.
Slicestor Software
The Cleversafe software that runs on each Slicestor. It basically stores, retrieves, and deletes slices; and also manages transactions at the level of the node.
Slice Store
The actual storage mechanism for the slices on the Slicestor. Examples are BDB, file, raw storage.
Slice Store Layer
An architectural layer of the Cleversafe dsNet access software which abstracts the physical storage of dispersed slices.
Slicing
Creating slices from a datasource (piece of data) using the IDA.
Smart Controller
A set of modules in the Cleversafe software which provides configurable read and write behavior and makes performance decisions based on various information.
Source Computer
In the Cleversafe system, a client machine used to access a dsNet through an access device. Contains or has access to the source data.
T
Threshold
See Write Threshold, Read Threshold.
Transaction
Transactions are a way to group dsNet operations into an atomic operation that can either be committed at once or rolled back.
U
No termsV
Vault
A defined collection of Datasources, a logical part of a dsNet Account where permissions can be granted and data storage options (like encryption, compression, IDA) can be configured. A Vault appears as a device when using the dsNet.
Vault Descriptor File
An XML file used for configurations of vault and transformation information in the Cleversafe software.
Vault Keys
Any keys used for slice encryption of signatures are stored in the vault ACL.
Vault Owner
A dsNet account with primary responsibility for a vault.
W
Width
See dsNet Width.
Write Threshold
The minimum number of Slicestors required for writing a datasource to the Cleversafe dsNet.
X
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Y
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Z
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