NonStop S-Series Planning and Configuration Guide (G06.26+)

The Planning and Configuration Process
HP NonStop S-Series Planning and Configuration Guide—523303-017
9-10
Enclosure Interleaving for Storage Devices
Recommendations
These recommendations are not required, except where they conform to the preceding
limitations.
For all disk, tape, and Open SCSI Devices
•
Configure the -P and -B paths to a device through different adapters, one on the X
fabric and the other on the Y fabric.
•
Configure a device to use the two processors that are in the same topology branch
as the adapter used for the -P path to the device. These processors are chosen by
default if no processors are specified in an SCF ADD command.
For All Disk Drives
•
Within a topology branch, interleave the adapters for mirrored disk volumes across
enclosures in a circular pattern. For example, in a topology branch consisting of
enclosures 04, 41, and 42, arrange the primary and mirror drives as follows.
For All Open SCSI Devices
•
Configure the -P and -B paths to an Open SCSI device to use adapters in the
same enclosure.
For All External Disk Drives
•
Configure the primary and mirror halves of a mirrored external disk volume to have
the same device ID in two different external disk modules.
•
Configure all paths to an external disk drive to use SACs with the same SAC
number on different 6760 adapters.
•
Configure the -P and -B paths to an external disk to use 6760 adapters in the same
enclosure. You can also configure the -P and -M paths to different enclosures, but
that is not necessary for fault tolerance, because the primary drive and mirror drive
are configured in different enclosures.
•
Configure the -M and -MB paths to an external disk to use 6760 adapters in the
same enclosure.
•
Configure the -P and -M paths to an external disk to use 6760 adapters on different
ServerNet fabrics.
Primary in Enclosure Mirror in Enclosure
04 41
41 42
42 04