Technical data

Figure 1–4: Two-Node Cluster with Two UltraSCSI DS-BA356 Storage Units
ID 8
ID 9
ID 10
ID 11
ID 12
ID 13
PWR
ID 5
PWR
Shared
SCSI
Bus
Clusterwide
/, /usr, /var
Member 1
Boot Disk
Member 2
Boot Disk
Quorum
Disk
UltraSCSI
BA356
ID 4
ID 14 or
redundant
power
supply
Host Bus Adapter (ID 7)
Network
Memory
Channel
Interface
Memory Channel
Host Bus Adapter (ID 6)
Memory Channel
Member
System
2
Member
System
1
Tru64
UNIX
Disk
ID 5
ID 4
ID 6
ID 3
ID 2
ID 1
ID 0
Data
disks
Do not use for
data disk. May
be used for
redundant power
supply.
Data
Disks
UltraSCSI
BA356
ZK-1590U-AI
This configuration, while providing more storage, has a single SCSI bus that
presents a single point of failure. Providing a second SCSI bus can allow the
use of the Logical Storage Manager (LSM) to mirror the clusterwide root (/),
/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.
1.5.3 Two-Node Configurations with UltraSCSI BA356 Storage Units
and Dual SCSI Buses
By adding a second shared SCSI bus, you now have the capability to use
LSM to mirror data disks, and the clusterwide root (/), /usr, and /var file
systems across SCSI buses.
1–12 Introduction