HP StorageWorks SAN Director Installation Guide (A7393-90009, May 2007)

SAN Director installation guide 27
The High Availability Manager controls access to the standby control processor, facilitates software
upgrades, prevents extraneous switchover activity, closes and flushes streams as needed, provides
flow control and message buffering, and supports a centralized active and standby state.
Reliability
The 4/256 SAN Director uses the following error detection and correction mechanisms to ensure the
reliability of all data inside the chassis:
• All data inside the switch protected by the Error Detection and Correction mechanism, which
checks for encoder errors and fault isolation (EDFI), such as cyclic redundancy checking (CRC),
parity checking, checksum, and illegal address checking
• Power-on self-test (POST)
• Dual control processors that enable hot, nondisruptive fast firmware upgrades
• Each control processor contains two serial ports and one Ethernet port. Offline control processor
diagnostics and remote diagnostics simplify troubleshooting. The standby control processor
continuously runs diagnostics to ensure it is operational, should a failover be necessary.
• Inter-IC (I
2
C) monitoring and control
Serviceability
The 4/256 SAN Director provides the following features to enhance and ensure serviceability:
• Modular design with hot-swappable components
• Redundant flash memory that stores two firmware images per control processor
• Extensive diagnostics and status reporting, along with a serial port to support an external,
country-specific modem for remote diagnostics and status monitoring
• Nonvolatile random-access memory (NVRAM), containing the HP serial number, manufacturer’s
serial number, revision information, and part number information
• Background health-check daemon
• Memory scrubber, self test, and bus ping to determine if a bus is not functioning
• Watchdog timers
• Status LEDs
• Predictive diagnostics analysis through Fabric Watch
• SNMP integration with higher-layer managers