HP ProLiant ML115 Server - Manual (Page 42)

38 MediaShield User’s Guide – Version 1.0
C HAPTER 4
Installing and Using the NVIDIA MediaShield Application
Managing Spare Disks
About Spare Disks
You can designate a hard drive to be used as a spare drive for a RAID 1, RAID 0+1 or
RAID 5 array
1
. The spare drive can take over for a failed disk. MediaShield RAID
supports two types of spare drives:
Free Disks
A free disk is a disk that is not part of any RAID array, but can be used by any available
RAID 1, RAID 0+1, or RAID 5 array that requires another disk when one of its disks
crashes or becomes unusable. The process is automatic and requires no user interaction.
Example: A system may have four hard disks where one disk is used to boot the OS, two
hard drives are set up in a mirrored array, and a fourth hard disk is set up as a free disk. If
one of the mirrored array drives fails, the free disk will be assigned automatically to the
mirrored array to replace the failed disk.
Dedicated Disks
A dedicated free disk is a disk that is assigned to a RAID 1, RAID 0+1, or RAID 5 array.
The dedicated disk is used by that array only when needed ‐ for example, during a system
crash where a RAID mirrored drive is broken. The dedicated disk can be used only by the
array that it is assigned to and not by any other array, unlike a free disk which can be used
by any available RAID 1, RAID 0+1, or RAID 5 array.
To mark a disk as dedicated (reserve it for use by a specific array), you must have at least
one free disk and you must also have at least two RAID 1, RAID 0+1, or RAID 5 arrays
created.
1. See Table 1.1, “Supported nForce Platforms and RAID Arrays” on page 2 for a matrix of supported
RAID levels.