Specifications

multiple environments
Business requirements and competitive pressures can dictate the need for a large set of
applications—both old and new. Often applications require different versions or revisions of
operating systems, different system parameter settings, and even different patch levels. And
performance can suffer from the interactions of applications with incompatible behaviors.
But nPartitions can solve the problem of different versions or revisions by running multiple
environments. With these partitions, a portion of the compute and I/O resources can be
configured to run an old copy of the operating system while the rest of the machine is updated to
run the newer software. Such a scheme can also be used to set up a test environment where new
software and operating systems can be installed, while leaving production applications to
continue operations without being affected.
Similarly, two HP Server rp8400 platforms can be set up such that each one runs the prime
partition of an MC/Serviceguard cluster as well as the backup partition of the other’s prime
partition. This eliminates single points of failure between the prime and backup partitions.
improved availability
Another use for nPartitions is to provide independence of failure or operation. If one partition must
be rebooted or taken down to perform an operating system upgrade, the other partition in the
system is not affected.
Unlike a traditional large SMP, nPartitions allow a server to be configured into a cluster of
independent systems. Since failure independence is provided by nPartitions, it is possible to
configure high availability clusters within the same complex, with each cluster consisting of two or
more partitions. In order to achieve maximum availability, the partitions making up the cluster can
be configured as high-availability partitions on different nodes; this ensures that no single
hardware or software failure can affect another cluster member, yet it retains the configuration
flexibility of a single pool of system resources.
more flexible scaling
Some applications may not have the ability to scale linearly with large numbers of CPUs.
However, nPartitions enable processors, memory, and I/O resources to be tailored to match
application-scaling characteristics. Moreover, as new application or operating system releases
provide improved scaling characteristics, nPartitions allow resources to be readjusted to optimize
application performance.
Here’s just one example: You could start off with an rp8400 configured with a pair of 8-way SMP
HP-UX partitions and, later, re-allocate the server’s resources to a 12-way SMP HP-UX partition
and a 4-way partition dedicated to Windows NT. Your hardware investment is protected even if
the hardware is re-allocated to a different operating system or application set with different
scaling properties.
what you gain with
To sum up, the major benefits of nPartitions are:
nPartitions
• increased server manageability and flexibility
• reduced total cost of ownership
• increased availability for mission-critical applications
Other benefits include:
• independent resource controls, I/O, and security in each partition
• ability to run multiple applications and/or different operating systems on a single system,
enabling the best use of computing resources while providing software fault and security isolation
• protection against software errors—a software error in one partition (including an OS failure) will
not bring down other partitions within the server
• protection against hardware errors in other nodes—a hardware error in a separate coherent
node will not bring down a partition in any other node
• protection against hardware errors in the same node—most hardware errors in the same node
will not bring down a peer partition in the same node
• protection against downtime due to configuration changes in another partition—configuration
changes in a different partition (such as online replacement or addition of a component, reboot,
shutdown, and so on) will not affect other active partitions on the same or a different node
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