HSG80 Enterprise/Modular Storage RAID Array Fibre Channel Solution Software V8.7A for Windows Release Notes (AA-RH0QL-TE, July 2003)

Operating Constraints
Release Notes – HSG80 Enterprise/Modular Storage RAID Array Fibre Channel Solution
Software Version 8.7A for Windows
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When migrating from SCSI-2 to SCSI-3, the controller checks for controller unit D0
and does not change modes until D0 (at all presented offsets) is deleted. One or more
LUNs are lost after the mode change. If you are planning to move from SCSI-2 to
SCSI-3, back up your data first. The data in LUN 0 (and any other offsets that map to
LUN 0) that was used in SCSI-2 requires that the data be moved to a different LUN. It
may be necessary to retrieve this data from a backup.
IMPORTANT: If multi-bus failover configurations or server clustering are employed in the
environment, there may be additional considerations regarding CCL usage during SCSI
migration procedures. Please see your multi-bus failover or server clustering documentation
prior to implementation.
In addition, there may be OS-based limitations on SCSI-3 usage to consider, particularly in
down-level versions of your OS. Please review your OS documentation prior to migration.
For more information, see the “What is the Command Console LUN?” and “Assigning
Unit Numbers Depending on SCSI_VERSION” sections of Chapter 1 in the HSG80
ACS Solution Software Version 8.7 Installation and Configuration Guide.
Operating Constraints
This section describes the operating constraints for ACS Version 8.7. An operating
constraint is a limitation placed on the operation of the controller. Other constraints on
host adapters or other system components may also apply. Keep these constraints in
mind to avoid problems and to help achieve the maximum performance from your
controller. See the documentation that came with your host server for more details.
External Cache Battery
StorageWorks recommends that you replace the External Cache Battery (ECB) every
two years to prevent battery failure.
If you are shutting down your controller for longer than one day, complete the
additional steps in “Shutting Down the Subsystem” in the HSG80 Array Controller
ACS Version 8.7 Maintenance and Service Guide. This prevents the ECB from
discharging during planned power outages.
Dual External Cache Battery Failures
The array controller cache policy provides for proper handling of a single ECB failure
as described in the HSG80 Array Controller ACS Version 8.7 Troubleshooting
Reference Guide. For dual ECB failures, it states that no failover occurs. For this
release, if a dual ECB failure is detected, both controllers are restarted.