Sonnet Technologies Web Management Tool - Manual (Page 75)

xix
The ATTO FastStream controller in the Fusion RX1600Fibre
provides instant hardware data protection and intelligence to
existing storage independent of the storage type.
To set up RAID groups refer to Configure Storage into RAID
Groups on page 7. The Fusion RX1600Fibre allows RAID
functionality. In general, the process begins with individual
drives called block devices.
Note: If a drive has corrupt or outdated configuration data, that
drive cannot be assigned to any RAID group. Ensure all drives are
configured properly. Refer to Ensure Drive Integrity on page 3 or
Removing RAID configuration data on page 34.
A RAID group is a virtual, independent single drive whose
data is written to physical drives according to a RAID
algorithm. The ATTO FastStream supports JBOD, DVRAID,
RAID Level 0, 1, 1+ 0, 4, 5 and 6.
RAID improves data accessibility and reliability during
normal operations, however, you still need a good backup
strategy for long-term protection of your data.
JBOD: Just a Bunch of Disks
JBOD configuration allows many individual drives to be
available for normal storage operations with no special data
protection by combining several drives into one large drive.
See
Figure B-1. A special case of a RAID group, multiple
physical drives are assigned to a JBOD RAID group and
their storage areas appear as a single spanned area of storage.
The Fusion RX1600Fibre supports 1 to 32 drives per JBOD-
configured RAID group.
RAID Level 0: Striping, No Redundancy
RAID Level 0 (striping) is based on the fact that increased
performance can be achieved by simultaneously accessing
data across multiple drives, increasing data transfer rates
while reducing average access time by overlapping drive
seeks. Drives are accessed alternately, as if stacked one on top
of the other.
RAID Level 0 provides no data protection. If
one drive fails, all data within that stripe set is lost. See
Figure B-2.
RAID Level 0 is used by applications requiring high
performance for non-critical data. The Fusion RX1600Fibre
supports 2 to 16 drives per RAID Level 0 group.
Appendix B - RAID Group Designs
Disk 1 Disk 2 Disk 3
Data 1 Data 5 Data 9
Data 2 Data 6 Data 10
Data 3 Data 7 Data 11
Data 4 Data 8 Data 12
JBOD (Just a Bunch of Disks)
Figure B-1
Disk 1
Data 1
Data 5
Data 9
Stripe 1
Stripe 2
Stripe 3
Disk 2
Data 2
Data 6
Data 10
Disk 3
Data 3
Data 7
Data 11
Disk 4
Data 4
Data 8
Data 12
RAID Level 0: Striping, No Redundancy
Figure B-2
WARNING: RAID improves data accessibility and
reliability during normal operations, however, you
still need a good backup strategy for long-term protection
of your data.