Chapter 8. Capacity upgrades 207
Draft Document for Review April 7, 2004 6:15 pm 6947ch08.fm

CBU deactivation

The process of deactivating CBU is simple and straightforward. The process starts by
quiescing the added CPs (normally the highest numbered) from all the logical partitions, and
varying them offline from the operating systems. Then from the HMC CBU activation panel,
perform a concurrent CBU undo.

CBU testing

Testing of disaster/recovery plans is easy with CBU. Testing can be accomplished by ordering
a diskette, calling the support center, or using the fast activation icon on the HMC.
Capacity BackUp operation example
Figure 8-10 on page 207 shows an example of a 2084-B16, software model 304 to a
2084-B16, software model 312 Capacity BackUp operation.
Figure 8-10 Capacity BackUp operation example
The PUs associated with Capacity BackUp are reserved for future use with CBU features (FC
7800) installed on the backup server. In this example, there should be 8 CBU features
installed on the backup server 2084-B16, software model 304. When the production server
2084-B16, software model 312 has an unplanned outage, the backup server can be
temporarily upgraded to the target model planned, 2084-B16, software model 312, to get the
capacity to take over the workload on the failed production server.
Furthermore, customers can configure systems to back each other up. For example, if a
customer uses two 2084-A08, software model 303 for the production environment, both can
have 3 CBU features installed (or even more). If one server has a disaster, the other one can
be upgraded up to the approximately total original CP capacity.
Automatic CBU enablement for GDPS
The intent of the GDPS CBU is to enable automatic management of the reserved PUs
provided by the CBU feature in the event of a server failure and/or a site failure . Upon
detection of a site failure or planned disaster test, GDPS will concurrently add CPs to the
Control
Unit Control
Unit
Control
Unit Control
Unit Control
Unit
ESCD
ESCD
Current Model:
2084-B16
Model 304
with 8 CBU features
(FC 7800)
Target Model:
2084-B16
Model 312
CBU Activation
Workload
Transfer
Production
Server
2084-B16
Model 304
8 CBUs
Backup
Server
2084-B16
Model 312 2084-B16
Model 312
Capacity
+ 8 CPs
Unplanned
Outage