HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Troubleshooting Guide (EK-G80TS-SA. C01, March 2005)

Troubleshooting Information
53HSG60 and HSG80 Array Controller and Array Controller Software Troubleshooting Guide
Dual external cache battery failures
The array controller cache policy provides for proper handling of a single ECB
failure as described in this guide. For dual ECB failures, it states that no failover
occurs. If a dual ECB failure is detected, both controllers are restarted.
Enabling mirrored writeback cache
Before configuring dual-redundant controllers and enabling mirroring, ensure that
the following conditions are met:
■ Each cache module is configured with the same size cache, 128 MB, 256 MB,
or 512 MB.
■ Diagnostics indicate that cache is good on both cache modules.
■ Both cache modules either:
— Have an ECB connected, and the UPS switch is set by one of the
following CLI commands:
SET controller NOUPS (no UPS is connected)
BA370 enclosure only: SET controller UPS=NODE_ONLY (a UPS is
connected)
— Do not have an ECB connected, and the UPS switch is set by the
following CLI command:
SET controller UPS=DATACENTER_WIDE
■ No unit errors are outstanding (for example, lost data or data that cannot be
written to devices).
■ Both controllers are started and configured in Failover mode.
For important considerations while configuring a subsystem for mirrored caching,
refer to the appropriate installation and configuration guide. To add or replace
DIMMs in a mirrored cache configuration, refer to the controller maintenance and
service guide.
Device Discovery Error report
The Device Discovery Error report contains information that the controller reports
to the maintenance console if it encounters errors in the Device Discovery Code
(see Figure 6 on page 54).