Glossary
MTBF
Mean Time Between Failure. A commonly used measure of system reliability, usually expressed in hours. Modern disk drives typically have an MTTR of 1 million hours or more.
MTTR
Mean Time To Repair. Includes the time taken to diagnose the failure, replace or repair faulty component(s) and restart the system so it is available to users. See MTBF.
NanoCopy
NanoCopy™ is a feature of the Hitachi Lightning 9900™ product line that enables time-consistent snapshots to be taken without stopping applications to flush in-flight data to disk. Since there is no system impact in taking a NanoCopy™ snapshot, snapshots can be made more frequently for faster recovery in the event of a failure. See also Hitachi TrueCopy™, ShadowImage™.
NDMP
Network Data Management Protocol (NDMP) is a standard protocol for network-based backup of network-attached storage. NDMP hides the unique hardware interfaces from third-party backup software that allows this software to execute on any NDMP compliant system on the network.
Node
See Fibre Channel.
NVM
Non-Volatile Memory is a term used to refer to battery backed up DRAM so that data will not be lost in the event of power failure.
NVRAM
Non-Volatile Random Access Memory such as static RAM will not lose data in the event that power is lost to the memory chips.
OLAP
On-line Analytic Processing. A type of Decision Support System in which real-time analytical software routines are applied to data.
OLTP
On-line Transaction Processing.
Off-site storage facility
A secure location, remote from the primary location, at which backup hardware, software, data files, documents, equipment, or supplies are stored.
