A-4
DuraStor 412R/6320SS/7320SS Installation and User’s Guide
four (4) host connections. You can enable or disable this feature
using Disk Array Administrator.
For a detailed discussion of each operating mode, see the section
that applies to your DuraStor storage subsystem:
For the DuraStor 6320SS, see the next section.
For the DuraStor 7320SS, see
.
Operating Modes – DuraStor 6320SS
Stand-Alone Mode
In stand-alone mode, the RAID controller operates autonomously.
The controller has two SCSI host I/O connector ports. They are
labeled in the diagrams as “CH 0” and “CH 3.” In single-port
mode, the “CH 3” connector becomes a drive channel providing
one additional drive channel for expansion.
Advantages:
■
Low cost entry-level RAID storage solution that is field
upgradeable.
■
Allows the use of dual host ports to maximize bandwidth and
host IOPs. (For example: this configuration is ideal for
sequential access patterns, where disks can supply more than
160 MB/sec of data to a host.)
■
Host system has multiple paths to each array (with host driver).
■
All arrays appear on both host ports at the same LUN positions
in Dual Port mode. (If both ports are connected to the same
host, the host will see a given array twice unless it does special
processing to detect duplicate paths to array. A host device
driver may provide this functionality.)
■
Hosts can detect redundant paths to an array by matching array
serial numbers from SCSI inquiry data.
Disadvantages:
■
The controller is a single point of failure.
■
Third-party software is required for upstream path fail-over.
DuraStor IUG - Online.book Page 4 Friday, July 19, 2002 3:06 PM
