User's Manual

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• Lower costs by centralizing storage management.
• iSCSI also simplifies the installation and on-going management of a SAN versus using
Fibre Channel.
With Open-E iSCSI, you can add storage to your existing network quickly, easily, and
most important cost-efficiently. Expensive hardware is no longer necessary. Take any
computer, a new rack server or an old desktop PC and exchange the system drive for
the Open-E iSCSI flash module. To store data Open-E iSCSI ENTERPRISE uses IDE
(ATA), SATA or SCSI hard drives and hardware RAID controllers.
Within a few minutes, you will have up to several hundred gigabytes available on your
network without much effort or any downtime.
2.4 RAID types
This manual is not intended to replace your RAID controller manual. But we want to
provide you with an overview of common RAID types so that you can make an
informed decision on which type to choose. Depending on whom you ask, RAID
means either Redundant Array of Independent Disks or Redundant Array of
Inexpensive Disks. Both are correct. In essence, you combine the capacity, speed and
security of several disks into one.
RAID 0 forms one large hard disk by concatenating stripes from each member drive.
Stripe size is configurable roughly between 64 KB and 1 MB. The result is a lightning-
fast RAID, but with no added security. One failing drive may ruin the entire RAID.
RAID 1 mirrors hard drives. By writing identical data onto more than one drive, security
is enhanced. A completely defective drive does not cause any loss of data. The
drawback is reduced performance and capacity.
RAID 5 combines data striping from RAID 0 with parity checking, therefore combining
speed and improved security. The loss of one drive is tolerable.
RAID 6 extends RAID 5 by adding an additional parity block, thus it uses block-level
striping with two parity blocks distributed across all member disks. It was not one of
the original RAID levels. The user capacity of a RAID 6 array is N-2, where N is the
total number of drives in the array. RAID 6 does not have a performance penalty for
read operations, but it does have a performance penalty on write operations due to
the overhead associated with the additional parity calculations.
RAID 10 is a combination of RAID 1 and 0, hence the name. Data is written in a striped
and mirrored configuration, providing high performance and robust security.