Raid 5Ee Logical Drives - Adaptec CDP-00278-02-A User Manual

RAID 5EE Logical Drives

A RAID 5EE logical drive—also known as a hot space—is similar to a RAID 5 array except that it includes
a distributed spare drive and must be built from a minimum of four disk drives.
Unlike a hot spare, a distributed spare is striped evenly across the disk drives with the stored data and
parity data, and can't be shared with other logical disk drives. A distributed spare improves the speed
at which the array is rebuilt following a disk drive failure.
A RAID 5EE logical drive protects your data and increases read and write speeds. However, capacity is
reduced by two disk drives' worth of space, which is for parity data and spare data.
In this figure, S represents the distributed spare, P represents the distributed parity data.
Disk Drive 1 250 GB
Disk Drive 2 250 GB
Disk Drive 3 400 GB
Disk Drive 4 400 GB
Disk Drives in Logical Drive
Proprietary and Confidential to PMC-Sierra, Inc.
Document No.: CDP-00278-02-A Rev. A, Issue:
Drive Segment Size
(Smallest Disk Drive)
1 S . . .
Disk Drive 1
Disk Drive 2 2 P . . .
Disk Drive 3
S 3 . . .
Disk Drive 4 P 4 . . .
Based on the drive segment sizes used:
RAID 5EE Logical Drive = 500 GB plus parity
and hot spare
maxView Storage Manager User's Guide
P
449
S
Unused Space = 150 GB
500
Unused Space = 150 GB
120