Product manual

CDA 7 5630 Product Manual
5-2 77 A1 69UP Rev00
These basic CDA 7 features provide protection against loss of system and data
availability due to a power loss or failed component. A redundant design allows
CDA 7 to remain online and operational during component repair. For example, if
a power supply fails, the remaining power supplies share the load until the failed
component is replaced. The system battery backup prevents any loss of data due to
a power failure.
The Dual-Initiator feature offers data availability protection against a CDA 7 disk
management component failure. With dual-initiator, each member of a disk
director pair shadows the functions of the other disk director. That is, each disk
director can service any or all of the devices attached to the disk director with
which it is paired. This feature does not, however, provide data availability in the
event of a disk device failure. Should CDA 7 detect a disk management hardware
failure, CDA 7 automatically reads from or writes to the disk devices it was unable
to communicate with via the other disk director in the pair.
5.1.2 CDA 7 Data Integrity Protection Features
The CDA 7 is designed with these data integrity features:
• Error checking, correction, and data integrity protection
• Disk error correction and error verification
• Cache error correction and error verification
• Periodic system checks
Error verification prevents temporary errors from accumulating and resulting in
permanent data loss. CDA 7 also looks at the error verification frequency as a
signal of a potentially failing component.
The periodic system check tests all components as well as microcode integrity.
CDA 7 reports errors and environmental conditions to the host system as well as
the Bull Competence Center.