NonStop NS-Series Planning Guide (H06.04+)

System Configuration Guidelines
HP Integrity NonStop NS-Series Planning Guide—529567-005
6-21
Fibre Channel Device Configuration Restrictions
Fibre Channel Device Configuration Restrictions
To avoid creating configurations that are not fault-tolerant or do not promote high
availability, these restrictions apply and are invoked by 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 FCSAs in the same module of an IOAM enclosure. Τhis
configuration compromises high availability. In a fully populated system, loss of one
FCSA can make up to 56 disk drives inaccessible on a single Fibre Channel
communications path. This configuration is allowed only, 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 FCSAs in the same module of an IOAM enclosure.
This configuration compromises high availability. In a fully populated system, loss
of one FCSA can make up to 56 disk drives inaccessible on a single Fibre Channel
communications path. This configuration is allowed only, but only if you override an
SCF warning message.
Fibre Channel Device Configuration Recommendations
These recommendations apply to FCSA and Fibre Channel disk module
configurations:
•
Primary Fibre Channel disk module connects to the FCSA F-SAC 1.
•
Mirror Fibre Channel disk module connects to the FCSA F-SAC 2.
•
FC-AL port A1 is the incoming port from an FCSA 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 an FCSA 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.
•
FCSA population in an IOAM enclosure is from slot 1 through slot 5.
•
G4SA population in an IOAM enclosure is from slot 5 through slot 1.