HighPoint RocketRAID 1740 - Manual (Page 9)

Introduction
Online RAID Level Migration
This term describes the ability to change one type of array (RAID level), into a
different type of array (changing a RAID 1 array into a RAID 10 array for example).
Data is still accessible during the migration process, and a base level of security is
still active.
OCE, ORLM and the RocketRAID 174x
The RocketRAID 174x supports both Online Capacity Expansion (OCE), and Online
RAID Level Migration (ORLM). Both features are supported by a single function - an
array can be transformed from one RAID level to another RAID level while simulta-
neously being resized, even under I/O load.
Spare disk
A spare disk is a single disk that can be used to automatically rebuild a redundant
array in case of drive failure. Spare disks may also be members of a RAID array. Any
available space on these disks may be used to rebuild other broken arrays.
Legacy disk
Disks attached to the RocketRAID 174x that contain valid partition tables will be
identified as legacy disks. A legacy disk attached to the RocketRAID 174x can be
accessed by the operating system, but cannot be used to create RAID arrays. A
legacy disk must be initialized before assigning it to an array.
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