Specifications

how partitions work
A hardware partition corresponds roughly to a single, standalone system. The rp8400 can be
subdivided into two partitions, each containing one or (usually) more cells that communicate
coherently over a high-bandwidth, low-latency crossbar fabric. Cells are grouped into physical
structures called cabinets or nodes.
Special programmable hardware in the cells defines the boundaries of a partition in such a
way that isolation from the actions of other partitions is enforced. Each partition runs its own
independent instance of the operating system (at first release, HP-UX 11i only). Non-clustered
applications cannot span partitions, since each partition runs its own instance of the OS—
essentially functioning as a standalone server. However, different partitions may be executing
the same or different revisions of an operating system. And at a future date, when Intel Itanium
Processor Family processors are available on the rp8400, different partitions will be able to
execute different operating systems—such as HP-UX, Windows NT
®
, and Linux—any two at
one time.
Each partition has its own independent CPUs, memory, and I/O resources, consisting of the
resources of the cells that make up the partition. Commands that are part of the system
management interface allow resources to be removed from one partition and added to another
without having to physically manipulate the hardware. With a future release of HP-UX, using the
related capabilities of dynamic reconfiguration (for example, online addition and online removal),
you will be able to add new resources to a partition or remove and replace failed modules while
the partition continues in operation.
The maximum number of cells in a single partition is four and the minimum is one. Each partition
must contain at least one cell that is attached to a core I/O card.
nPartition configurations
As previously mentioned, the rp8400 can be divided into two independent hardware partitions.
In a partitioned configuration, system resources such as I/O slots, core I/O, disks, and
removable-media devices are evenly split between the two partitions. There is no flexibility to
otherwise divide these components. For example, it is not possible to include 12 I/O slots in
partition 0 and four I/O slots in partition 1; the split must be even.
On the other hand, cell boards and their sub-components (processors and memory) can be
unevenly divided in a partitioned system. The basic rule is that cell 0 and cell 1 must be in
separate partitions; after that, cells 2 and 3 can both be assigned to partition 0, or both to
partition 1, or divided between the two partitions. The following table summarizes the resource
split between hardware partitions.
cells (req) I/O slots
core I/O
(req)
disk/media bays optional cells
Partition 0 Cell 0 8 1 2/1 Cell 2 and/or 3
Partition 1 Cell 1 8 1 2/1 Cell 2 and/or 3
reconfiguring partitions
You can increase or reduce the processing power of a partition by adding or deleting cells. (For
the first release of the rp8400 with HP-UX 11i, you must shut down the operating system running
on the affected partitions before moving cells, and before configuration changes will take effect.)
Though HP-UX 11i does include commands for some configuration tasks, HP recommends you use
the Partition Manager (parmgr) to configure partitions.
The combination of the rp8400 and HP-UX 11i supports hardware partitioning. Hardware-based
partition configuration changes may require a reboot of the partition, depending upon the
configuration change. The reboot of the partition only affects the partition that is being
reconfigured; the other partition is not affected and will continue to execute without interruption.
dynamic reconfiguration
In a future HP-UX release, dynamic hard partitions will be supported. Dynamic partitions mean
that partition configuration changes do not require a reboot of the partition. Virtual partitioning
within HP-UX 11i also provides additional options for dynamic reconfiguration without having to
reboot the changed partition.
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