IBM eServer zSeries 900 Technical Guide

Chapter 1. zSeries 900 overview 13

1.4 Concurrent upgrades

The z900 servers have concurrent upgrades capability via the Capacity Upgrade on Demand

(CUoD) function. This function is also used by Customer Initiated Upgrades (CIUs) and by the

Capacity BackUp (CBU) feature implementation.

Capacity Upgrade on Demand

Capacity Upgrade on Demand offers server upgrades via Licensed Internal Code (LIC)

enabling. CUoD can concurrently add processors (CPs, IFLs or ICFs), memory, and channel

cards to an existing configuration, when no hardware changes are required, resulting on an

upgraded server.

Adequate planning is required to exploit this function. Proper MCM type and memory card

sizes must be used, and the Plan Ahead feature with concurrent conditioning enablement is

required to ensure that all required infrastructure is available for I/O upgrades.

Customer Initiated Upgrade

Customer Initiated Upgrades are Web-based solutions for customers ordering and installing

upgrades via the IBM Resource Link and the z900 Remote Support Facility (RSF). A CIU

requires a special contract and registration with IBM. The CIU uses the CUoD function to

allow concurrent upgrades for processors (CPs, IFLs and ICFs) and memory, resulting in an

upgraded server.

As a CUoD, it also requires proper planning with respect to MCM type and memory card

sizes. CIU is

not available for I/O upgrades.

Capacity BackUp (CBU)

Capacity BackUp (CBU) is a temporary upgrade for customers who have a requirement for a

robust disaster/recovery solution. It requires a special contract with IBM. CBU can

concurrently add CPs to an existing configuration when another customer’s servers are

experiencing unplanned outages.

The proper number of CBU features, one for each “backup” CP, must be ordered and installed

to restore the required capacity under disaster situations. The CBU activation can be tested

for disaster/recovery procedures validation and testing.

Since this is a temporary upgrade, the original configuration must be restored after a test or

disaster recovery situation.

1.5 64-bit z/Architecture

The zSeries is based on the z/Architecture, which is designed to eliminate bottlenecks

associated with the lack of addressable memory and automatically directs resources to

priority work through Intelligent Resource Director (IRD). The z/Architecture is a 64-bit

superset of the ESA/390 architecture.

z/Architecture is implemented on the z900 to allow full 64-bit real and virtual storage support.

A maximum 64 GB of real storage is available on z900 servers. z900 can have logical

partitions using 31-bit or 64-bit addressability.

The z/Architecture has:

򐂰 64-bit general registers.

򐂰 New 64-bit integer instructions.