J2 485 System Manual
Version 1.0 May 19, 2012
51
RAID
RAID Overview
The J2 485 uses the Intel Matrix Storage Technology to allow the two internal 2.5 inch
hard drives to be configured as a RAID array. The J2 485 supports RAID 0, RAID 1 and
Intel Matrix RAID which combines the benefits of two RAID volumes in a single RAID
array.
If you are not currently familiar with RAID arrays Intel has a good white paper on the
subject at:
http://www.intel.com/design/chipsets/applnots/310855.htm
There are a number of benefits to using the RAID feature:
Protection
is one benefit. When using a RAID 1 array, data is protected by mirroring.
The primary RAID volume is duplicated automatically on the second drive, a mirror
image of the first. If one of the two hard drives fails, the system will still keep working.
The bad hard drive can be replaced while the system is running. This is called hot
swapping or hot plug. The new drive will automatically be updated to a mirror image of
the working drive.
Performance
is another feature RAID can provide. When configured as a RAID 0 array
the two drives in the RAID array are striped. With striping, data is split between two
drives. This allows the J2 485 to read the data more than twice as fast as with a single
drive. The performance can be accomplished more quickly because the Intel RAID driver
also uses the AHCI NCQ function built into the SATA drives.
Protection and Performance
can be mixed using an Intel Matrix RAID configuration,
whereby a RAID 1 and RAID 0 can be setup on the same RAID array. Mission critical
data can be stored in the RAID 1 volume and data requiring performance can be stored on
the RAID 0 volume.
AHCI
AHCI stands for Advanced Host Controller Interface and is a feature of the SATA
interface that allows for Hot Swapping and Native Command Queuing (NCQ).
NCQ allows multiple commands to be sent to the hard drive at one time. The drive
decides the best way to order the commands for the best performance from the drive.
AHCI is enabled when RAID mode is selected in the BIOS setup.
To use AHCI drivers from Intel the BIOS must be set to RAID,
not AHCI
. The AHCI
mode uses the same drivers as used for RAID. Follow the instructions for installing the
RAID drivers, however set the HDD as a
Non-RAID Disk
in the RAID BIOS setup.
