Mapping

Conversion between two data addressing spaces. Most commonly used in RAID Advisory Board publications to refer to conversion between member disk physical block addresses and block addresses of the virtually disks presented to the operating environment by Array Management Function.

Mbyte

Shorthand for 1,000,000 bytes. Pronounced megabyte. RAID Advisory Board publications use the 1,000,000 convention commonly found in data transfer-related literature rather then the 1,048,576 convention common in computer system random access memory and software literature

Member (disk)

A disk that is in use as a member of a disk array. A disk may be a member of an array at times and used independently at other times.

Minimum Strip Size

The least common denominator of the member strip sizes of a disk array. The RAID Advisory Board specification of disk array data mapping requires all array member strip sizes to be multiples of the minimum strip size.

Mirroring

A form of RAID in which the Array Management Function maintains two or more identical copies of data on separate disks. Also known as RAID Level 1 and disk shadowing

Mirrors, Mirrored Disks

The disks of a mirrored array

Mirrored Array

Common tem for a disk array that implements RAID Level 1, or mirroring to protecting data against loss due to disk or channel failure.

Monitor (Program)

A program that executes in an operating environment and keeps track of system resource utilization. Monitors typically record CPU utilization, I/O request rates, data transfer rates, RAM utilization, and similar statistics. A monitor program, which may be an integral part of an operating system, a separate software product, or a part of a related component, such as a database management system, is a necessary prerequisite to manual I/O load balancing.

Multi-threaded

Having multiple concurrent or pseudo-concurrent execution sequences. Used to descried processes in computer systems. Multi-threaded processes are one means by which I/O request-intensive applications can make maximum use of disk arrays to increase I/O performance.