Technical data

the member system and storage device. Be aware though, the
KZPSA-BB is not an UltraSCSI device and therefore only works
at fast-wide speed (20 MB/sec).
The following sections describe how to prepare and install cables for storage
configurations on a shared SCSI bus using UltraSCSI hubs and the HSZ70
and HSZ80 RAID array controllers, or the RAID Array 3000.
3.7.1 Configuring Radially Connected TruCluster Server Clusters
with UltraSCSI Hardware
Radial configurations with RAID array controllers allow you to take
advantage of the benefits of hardware mirroring, and to achieve a
no-single-point-of-failure (NSPOF) cluster. Typical RAID array storage
subsystems used in TruCluster Server cluster configurations are:
• RA7000 or ESA10000 with HSZ70 controller
• RA7000 or ESA10000 with HSZ80 controller
• RA8000 or ESA12000 with HSZ80 controller
• RA3000 with HSZ22 controller
______________________ Note _______________________
You cannot achieve a NSPOF configuration with a RA3000.
When used with TruCluster Server, one advantage of using a RAID array
controller is the ability to hardware mirror the clusterwide root (/) file
system, member system boot disks, swap disk, and quorum disk.
HSZ70 or HSZ80
When used in a dual-redundant configuration, Tru64 UNIX Version 5.1A
supports both transparent failover, which occurs automatically, without host
intervention, and multiple-bus failover, which requires host intervention
for some failures.
______________________ Note _______________________
Enable mirrored cache for dual-redundant configurations to
further ensure the availability of unwritten cache data.
Use transparent failover if you only have one shared SCSI bus. Both
controllers are connected to the same host and device buses, and either
controller can service all of the units if the other controller fails.
Shared SCSI Bus Requirements and Configurations Using UltraSCSI Hardware 3–17