Technical data

this slot can be used for a second power supply to provide fully
redundant power to the storage shelf.
With the use of the cluster file system (see the Cluster Administration
manual for a discussion of the cluster file system), the clusterwide root (/),
/usr, and /var file systems can be physically placed on a private bus of
either of the member systems. But, if that member system is not available,
the other member systems do not have access to the clusterwide file systems.
Therefore, we do not recommend placing the clusterwide root (/), /usr, and
/var file systems on a private bus.
Likewise, the quorum disk can be placed on the local bus of either of the
member systems. If that member is not available, quorum can never be
reached in a two-node cluster. We do not recommend placing the quorum
disk on the local bus of a member system because it creates a single point of
failure.
The individual member boot and swap partitions can also be placed on a local
bus of either of the member systems. If the boot disk for member system
1 is on a SCSI bus internal to member 1, and the system is unavailable
due to a boot disk problem, other systems in the cluster cannot access the
disk for possible repair. If the member system boot disks are on a shared
SCSI bus, they can be accessed by other systems on the shared SCSI bus for
possible repair.
By placing the swap partition on a system’s internal SCSI bus, you reduce
total traffic on the shared SCSI bus by an amount equal to the system’s
swap volume.
TruCluster Server Version 5.1A configurations require one or more disks to
hold the Tru64 UNIX operating system. The disks are either private disks
on the system that will become the first cluster member, or disks on a shared
bus that the system can access.
We recommend that you place the clusterwide root (/), /usr, and /var file
systems, member boot disks, and quorum disk on a shared SCSI bus that
is connected to all member systems. After installation, you have the option
to reconfigure swap and can place the swap disks on an internal SCSI bus
to increase performance. See the Cluster Administration manual for more
information.
1–10 Introduction