Service manual

System Overview 1-37
For a full discussion of soft partitions and how to create them, see the
AlphaServer GS80/160/320 Getting Started with Partitions.
Applying the rules in Table 1–6 to a GS160 with four QBBs, a customer might
set up a system as shown in Table 1–7. This system has three soft partitions
each with the required resources to run an instance of an operating system.
Currently, only OpenVMS supports soft partitions. The configuration shows
that soft partitions are not confined to QBB boundaries and through shared
memory and the Galaxy console functions, the instances of the operating
systems running in each partition know about each other.
Results of Soft Partitioning
1. A soft partition is a subset of system resources capable of running an
operating system.
2. Partitions know about each other’s existence and can share resources.
(System faults will crash all partitions though.)
3. Errors: See Section 3.11.
• All errors that are faults crash all partitions.
• Uncorrectable errors that are not faults affect only the soft partition
experiencing the error.
• Correctable errors affect only the hard partition experiencing the error.
4. From a console/operating system point of view, partitions look alike – QBBs,
CPUs, and IOPs are numbered starting with 0 in each partition.
NOTE: Result 4 can lead to confusion. Say two partitions with two QBBs in
each have been created in a system with four QBBs (0-3). If you issue
the command $ stop/cpu/poweroff 7 in one partition, the command
may target CPU3 in QBB1. If you issue the same command in the other
partition, the command may target CPU3 in QBB3. To minimize this
effect, create a hardware drawing of the partitions to help translate
software IDs to physical locations.