Compaq TruCluster Server AA-RHGWB-TE Manual page 33

multiple BA356 storage units can be used on the same SCSI bus to allow
more devices on the same bus.
Figure 1–4 shows the configuration in Figure 1–3 with a second UltraSCSI
BA356 storage unit that provides an additional seven disks for highly
available applications.
Figure 1–4: Two-Node Cluster with Two UltraSCSI DS-BA356 Storage Units
Member
System
1
Memory Channel
Host Bus Adapter (ID 6)
UltraSCSI
BA356
Tru64
UNIX
Disk
Clusterwide
/, /usr, /var
Member 1
Boot Disk
Member 2
Boot Disk
Quorum
Disk
ID 4
Data
disks
ID 5
Do not use for
data disk. May
be used for
redundant power
supply.
PWR
This configuration, while providing more storage, has a single SCSI bus that
presents a single point of failure. Providing a second SCSI bus would allow
the use of the Logical Storage Manager (LSM) to mirror the /usr and /var
file systems and the data disks across SCSI buses, removing the single SCSI
bus as a single point of failure for these file systems.
Network
Member
System
Memory
2
Channel
Interface
Memory Channel
Host Bus Adapter (ID 7)
UltraSCSI
Shared
BA356
SCSI
Bus
ID 0
ID 1
ID 2
Data
ID 3
Disks
ID 4
ID 5
ID 6
PWR
ZK-1590U-AI
ID 8
ID 9
ID 10
ID 11
ID 12
ID 13
ID 14 or
redundant
power
supply
Introduction 1–11