Infrastructure
Cleversafe Dispersed Storage contains 3 layers: a Source Computer, an Accesser, and Slicestors for storage.
Source Computers
Source computers are used to submit, retrieve or delete end users’ data by connecting to an Accesser using an iSCSI interface. Source computers perform standard file system operations (e.g. copy, modify and delete), and end users may create, modify and delete files using any file-based software.
Typically, one iSCSI Initiator connects to one iSCSI target.
This release does not document how to connect multiple iSCSI initators to multiple iSCSI targets and has not been thoroughly tested for such scenarios.
Accessers
An Accesser is the iSCSI target and is mounted as a drive to the Source Computer. The Accesser software transparently stores and retrieves slices to the separate Slicestors even though the files appear as singular files within the file system on the Source Computer
Slicestors
Cleversafe Dispersed Storage employs Slicestors to store unique Slices (not copies of data). Due to the Cauchy Reed-Solomon Information Dispersal Algorithm (IDA) used in Cleversafe Dispersed Storage software, this design allows complete data retrieval if the threshold number of Slicestors are available.
Infrastructure Configurations
The intended configuration is to use different machines for each layer and each Slicestor. However, for various reasons, you might choose to run the software on a different configuration:
- Default Configuration. Within this option, the Slicestors could be set up on any combination of one machine to the full width of the dsNet. Virtual Machines would be used if there is more than one Slicestor on a machine. This configuration has been tested extensively by Cleversafe.
- Try out Configuration. The iSCSI initiator is installed on one machine, and a second machine has the Accesser and Slicestors installed. Useful when hardware is not available for a full setup.
- Developer Configuration. All the software is installed on one machine, useful when hardware is not available for a full setup.
Both the Try out Configuration and the Developer Configuration have not been extensively tested by Cleversafe. We have identified problems with running the iSCSI initiator and the Accesser on the same machine - transfer of large files (>50 MB) do not work.
Items such as DNS/IP addresses, port, and IQN can be configured for the machines.
