Hard partitioning is a physical separation of computing resources
by hardware-enforced access barriers. It is impossible to read or
write across a hard partition boundary, and there is no resource
sharing between hard partitions.
Soft partitioning is a separation of computing resources by
software-controlled access barriers. Soft partitions (subpartitions
in some contexts) enable the sharing of hardware resources among
several operating systems. Read and write access across a soft partition
boundary is controlled by the operating system or applications.
OpenVMS Galaxy is an implementation of soft partitioning.
How customers choose to partition their new AlphaServer ES
or GS series systems depends on their computing environments and
application requirements. When planning for partitioning, the amount
of memory required by the applications and which operating system
to run should be considered. When deciding how to configure an OpenVMS
system that supports partitioning, look at the following questions:
How many hard partitions do I need?
How many soft partitions do I need?
How small can I make the partitions? Multiple hard partitions provide the maximum hardware security
between partitions. A single soft partition running in a hard partition
is equivalent to its running in a dedicated machine.
Multiple
soft partitions within a given hard partition allow sharing resources
such as CPUs and memory, and provide performance advantages.