Product specifications

Infortrend
4-12
Before proceeding with RAID migration, make sure you have sufficient
free capacity or unused drives in your RAID array. RAID6 arrays require
at least four (4) member drives and use additional capacity for the
distribution of secondary parity. For example, if you want to migrate a
RAID5 array consisting of three (3) drives to RAID6, one additional disk
drive must be available.
The different features of RAID5 and RAID6 arrays is summarized as
follows:
RAID5 RAID6
Min. No. of
Member Drives
3 4
Raw Capacity N N
Usable Capacity N-1 (parity drive) N-2 (parity drives);
N>=2
• If individual disk capacity = 100G,
• Capacity of a 4-drive RAID5 =
(4-1) x 100G = 300G
• Capacity of a 4-drive RAID6 =
(4-2) x 100G = 200G
Redundancy 1 drive failure 2 drive failures
NOTE:
Some specific functions associate with RAID migration only work with
certain product models.
4.5.1 Requirements for Migrating a RAID5 Array
The preconditions for migrating a RAID5 array is:
The usable capacity of the RAID6 array should be equal or larger
than the usable capacity of the original RAID5 array.
To obtain the larger capacity, you can:
1). Add Drive(s): Include one or more disk drives into the array.
2). Copy and Replace: Use larger disk drives in the array to replace the
original members of the RAID5 array.
4.5.2 Migration Methods
The conditions for migrating an array to RAID6 is diagrammed as
follows: