NonStop NS14000 Planning Guide (H06.08+)

Configurations for Fibre Channel Devices
The Integrity NonStop NS14000 system supports up to eight Fibre Channel ports and 32 Fibre
Channel disk modules are possible when using daisy-chained configurations, with identification
depending on the ServerNet connection to the Fibre Channel ports on the VIO enclosure.
Configuration Restrictions for Fibre Channel Devices
To avoid creating configurations that are not fault-tolerant or do not promote high availability,
these restrictions apply and are invoked by Subsystem Control Facility (SCF):
• Primary and mirror disk drives cannot connect to the same Fibre Channel loop. Loss of the
Fibre Channel loop makes both the primary volume and the mirrored volume inaccessible.
This configuration inhibits fault tolerance.
Disk drives in different Fibre Channel disk modules on a daisy-chain connect to the same
Fibre Channel loop.
• The primary path and backup Fibre Channel communication links to a disk drive should
not connect to Fibre Channel ports in the same module of a VIO enclosure. In a fully
populated system, loss of one Fibre Channel port can make up to 56 disk drives inaccessible
on a single Fibre Channel communications path. This configuration is allowed, but only if
you override an SCF warning message.
• The mirror path and mirror backup Fibre Channel communication links to a disk drive
should not connect to Fibre Channel ports in the same module of a VIO enclosure. In a fully
populated system, loss of one Fibre Channel port can make up to 56 disk drives inaccessible
on a single Fibre Channel communications path. This configuration is allowed, but only if
you override an SCF warning message.
Recommendations for Fibre Channel Device Configurations
These recommendations apply to Fibre Channel ports and Fibre Channel disk module
configurations:
• Primary Fibre Channel disk module connects to the Fibre Channel port F-SAC 1.
• Mirror Fibre Channel disk module connects to the Fibre Channel port F-SAC 2.
• FC-AL port A1 is the incoming port from a Fibre Channel port on the VIO enclosure or from
another Fibre Channel disk module.
• FC-AL port A2 is the outbound port to another Fibre Channel disk module.
• FC-AL port B2 is the incoming port from a Fibre Channel port on the VIO enclosure or from
a Fibre Channel disk module.
• FC-AL port B1 is the outbound port to another Fibre Channel disk module
• In a daisy-chain configuration, the ID expander harness determines the enclosure number.
Enclosure 1 is always at the bottom of the chain.
• Fibre Channel ports are located in slots 1 and 7c of a VIO enclosure.
• Ethernet ports are located in slots 6b, 6a/7a, and 7b of a VIO enclosure.
• The group number for a VIO enclosure is 100.
• In systems with two or more cabinets, primary and mirror Fibre Channel disk modules
reside in separate cabinets to prevent application or system outage if a power outage affects
one cabinet.
• With primary and mirror Fibre Channel disk modules in the same cabinet, the primary Fibre
Channel disk module resides in a lower U than the mirror Fibre Channel disk module.
• Fibre Channel disk drives are configured with dual paths.
• Where possible, Fibre Channel ports and Fibre Channel disk modules are configured with
four Fibre Channel ports and four Fibre Channel disk modules for maximum fault tolerance.
If Fibre Channel ports are not in groups of four, the remaining Fibre Channel ports and Fibre
Channel disk modules can be configured in other fault-tolerant configurations such as with
Fibre Channel Devices 87