Audible 2220 manual Understanding RAID Concepts and Terminology

Understanding RAID Concepts and Terminology

The following concepts and terminology is commonly used when describing the functions of the RocketRAID 2220 Host Adapter.

Disk initialization

Initializing a disk writes necessary RAID configuration information to that disk. Disks must be initialized before configuring them into RAID arrays. The initialization process will destroy all data on the disk.

Disk Status

New	The disk contains no data and has not been initialized.
Initialized	The disk has been initialized and can be used for array creation.
Configured	The disk has been assigned to one or more arrays, or configured as a spare disk.
Legacy	The disk was used on other controllers before use with the RocketRAID 2220 (see legacy
	disk below).

Array initialization

A redundant array (RAID5, RAID1, RAID10) needs to be initialized to ensure full performance and reliability. Non-redundant arrays (RAID0, JBOD) do not need to be initialized.

When you create a redundant array using the RocketRAID 2220 controller’s BIOS Configuration Utility, it will create the array in un-initialized state. The initialization process can be completed after installing the driver and management software.

When creating an array using the HighPoint RAID Management Console software, you can specify an initialization option (Skip initialization, foreground and background).

Foreground initialization

Foreground initialization will zero-out all data on the array. The array is not accessible by the operating system until initialization is complete.

Background initialization

Background initialization allows the array to be used immediately. For RAID1 and RAID10 arrays, initialization will results in data being duplicated identically to the mirror pair. For RAID5 arrays, initialization will result in parity being generated from all array members.

Note: An un-initialized RAID1 or RAID10 array can still provide redundancy in case of a disk failure. A RAID5 array, however, is not fault -tolerant until initialization is finished.

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