Technical Guide Book for PowerVault MD3200MD3220
Table 7.
RAID Configuration Support
RAID-0
Data is striped
Description
across multiple
physical disks.
Min # of physical
disks in a disk
1
group
Max # of physical
disks in a disk
96
group
Usable capacity as
100%
% of raw capacity
Application
IOPS | MB/s
Performance due
to parallel
Advantages
operation of the
access
No redundancy.
Disadvantages
One physical disk
fails, data is lost
Virtual Disk Configuration
A virtual disk is a logical structure on a storage array
for data storage. A virtual disk is created by slicing a
disk group into a stripe set with a defined capacity.
Each disk group supports up to one or more virtual disks
and a
maximum of 256 virtual disks
of storage system. During the virtual disk creation
process, the user specifies the capacity of the virtual
disk and the virtual disk name. Additional settings
include preferred controller ownership and a virtual
disk-to-LUN mapping parameter (See Storage
Partitioning section).
RAID-1 and 1+0
RAID-5
Physical disks operated
independently with data
Data is "mirrored"
and parity blocks
to another
distributed across all
physical disk.
physical disks in the
group.
2
3
96
30
50%
66.67% to 96.67%
IOPS
IOPS | MB/s
Good for reads, small
Performance as
IOPS, many concurrent
multiple requests
IOPS and random I/Os.
can be fulfilled
Parity utilizes small
simultaneously
portion of raw capacity.
Storage costs are
Writes are particularly
doubled
demanding
per MD3200 series
Disk
1
RAID-6
Physical disks operated
independently with data
and dual parity blocks
are distributed across all
physical disks in the
group.
4
30
50% to 93.33%
IOPS | MB/s
Same advantages as
RAID-5 but with better
data protection. Two
hard drives can fail
without losing access to
data.
Overhead on writes will
be slightly more
demanding than RAID-5
Disk Group A
Disk
Disk
Disk
2
4
3
Virtual Disk
30