Completed Standards
Completed Standards
Common RAID Disk Data Format
(DDF)
The Common RAID Disk Data Format specification defines a standard data structure describing how data is formatted across the disks in a RAID group. The Disk Data Format (DDF) structure allows a basic level of interoperability between different suppliers of RAID technology. The Common RAID DDF structure benefits storage users by enabling data-in-place migration among systems from different vendors.
IP-Based Drive Management Specification
The IP Drive Management Specification describes the management features and functions of a storage device class known as IP Based Drives. It includes a taxonomy covering the scope of involved device capabilities.
iSCSI Management API (IMA)
The iSCSI Management API defines a standard interface that applications can use to perform iSCSI management independent of the vendor of the iSCSI HBA. The IMA was designed to be implemented using a combination of a library and plugins.
An IMA library provides the interface that applications use to perform iSCSI management. Among other things, the library is responsible for loading plugins and dispatching requests from a management application to the appropriate plugin(s). Plugins are provided by iSCSI HBA vendors to manage their hardware.
Typically, a plugin will take a request in the generic format provided by the library and then translate that request into a vendor specific format and forward the request onto the vendor’s device driver. In practice, a plugin may use a DLL or shared object library to communicate with the device driver. Also, it may communicate with multiple device drivers. Ultimately, the method a plugin uses to accomplish its work is entirely vendor specific.
Linear Tape File System (LTFS)
Format Specification
The LTFS Format Specification defines a file system format separate from any implementation on data storage media. Using this format, data is stored in LTFS Volumes. An LTFS Volume holds data files and corresponding metadata to completely describe the directory and file structures stored on the volume.
The LTFS Format has these features:
An LTFS Volume can be mounted and volume content accessed with full use of the data without the need to access other information sources.
- Data can be passed between sites and applications using only the information written to an LTFS Volume.
- Files can be written to, and read from, an LTFS Volume using standard POSIX file operations.
The LTFS Format is particularly suited to these usages:
- Data export and import.
- Data interchange and exchange.
- Direct file and partial file recall from sequential access media.
- Archival storage of files using a simplified, self-contained or “self-describing” format on sequential access media.
Multipath Management API (MMA)
The Multipath Management API allows a management application to discover the multipath devices on the current system and to discover the associated local and device ports.
An implementation of the API may optionally include active management (failover, load balancing, manual path overrides). The API uses an architecture that allows multiple MP drivers installed on a system to each provide plugins to a common library.
The plugins can support multipath drivers bundled with an OS, or drivers associated with an HBA, target device, or volume manager.
This API can be used by host-based management applications and will also be included in the SMI-S Host Discovered Resources Profile for enterprise-wide multipath discovery and management. A client of the API should be able to move between platforms by simply recompiling.