Dot Hill Systems SANnet II 200, Инструкция по установке, эксплуатации и обслуживанию

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1-4 SANnet II 200 SCSI Array Installation, Operation, and Service Manual • June 2005
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Channel 6 is a redundant controller communication (RCCOM) channel. Channel 6
must remain a dedicated RCCOM channel. RCCOM provides the communication
channels by which two controllers in a redundant RAID array communicate with
one another. This communication enables the controllers to monitor each other, and
includes configuration updates, and control of cache.
For more host and drive channel information, see Chapter 4.
1.3.1 Redundant Configuration Considerations
This section provides information about setting up redundant configurations for
increased reliability. For more detailed information about configuration requirements,
refer to the
SANnet II Family RAID Firmware User’s Guide and the SANnet II Family
Best Practices Manual .
SCSI is applied to storage configurations with topologies that aim to avoid loss of data
because of component failure. As a rule, the connections between source and target
should be configured in redundant pairs.
The recommended host-side connection consists of two or more host bus adapters
(HBAs). Each HBA is used to configure a connection between the host computer and
the array.
In the unlikely event of controller failure, the standby channels on the remaining
controller become an I/O route serving the host I/O originally directed to the failed
channel on its pair of controllers. Moreover, application failover software should be
running on the host computer to control the transfer of I/O from one HBA to another
in case either data path fails.
1.4 Device Identification
A label on the lower lip of an array chassis, underneath the front bezel, indicates
whether it is a JBOD array or a RAID array. For instance, “SANnet II 200 AC JBOD”
refers to an alternating-current version of a SANnet II 200 JBOD array, “SANnet II
200 DC JBOD” refers to a direct-current version of a JBOD array, and “SANnet II 200
AC RAID” refers to an alternating-current version of a RAID array. Similarly, using a
UNIX command such as
probe-scsi-all
provides similar information, using an
“R” designator for RAID arrays and a “J” designator for disks in a JBOD array. For
example, “SANnet II 200L J” identifies a JBOD array with SAF-TE firmware version
1170, and “SANnet II 200L R” identifies a SANnet II 200 SCSI RAID array with
firmware version 1170.
For a list of supported racks and cabinets, refer to the release notes for the model of
array that you are installing.