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

System Configuration Guidelines
HP Integrity NonStop NS-Series Planning Guide—529567-005
6-28
Example IOAM and Fibre Channel Disk Module
Configurations
Daisy-Chain Configurations
When planning for possible use of daisy-chained disks, consider:
The illustration on the next page shows an example of cable connections between the
two FCSAs and four Fibre Channel disk modules in a single daisy-chain configuration.
A second equivalent configuration, including an IOAM enclosure, two FCSAs, four
disk-drive enclosures with ID expander, is required for fault-tolerant mirrored disk
storage. Installing each mirrored disk in the same corresponding FCDM and slot
Daisy-Chained Disks
Recommended for ...
Daisy-Chained Disks Not
Recommended for ...
Requirements for
Daisy-Chain
1
Cost-sensitive storage and
applications using low-
bandwidth disk I/O
Many volumes in a large Fiber
Channel loop. The more
volumes that exist in a larger
loop, the higher the potential
for negative impact from a
failure that takes down a Fiber
Channel loop.
All daisy-chained Fibre
Channel disk modules
reside in the same cabinet
and are physically grouped
together.
Where low-cost,
high-capacity data storage
is important.
Applications with a highly
mixed workload, such as
transaction data bases or
applications with high disk I/O.
ID expander harness with
terminators is installed for
proper Fibre Channel disk
module and drive
identification.
FCSA for each Fibre
Channel loop installs in a
different IOAM module for
fault tolerance.
Two Fibre Channel disk
modules minimum, with four
Fibre Channel disk modules
maximum per daisy-chain.
1
See Fibre Channel Devices on page 6-18.