## 2.7.6 Capacity Backup Upgrade 

Capacity Backup Upgrade (CBU) delivers temporary backup capacity in addition to the capacity that an installation might have available in numbers of assigned CPs, IFLs, ICFs, zIIPs, and optional SAPs. CBU has the following types: 

GLYPH<SM590000> CBU for CP 

GLYPH<SM590000> CBU for IFL 

GLYPH<SM590000> CBU for ICF 

GLYPH<SM590000> CBU for zIIP 

GLYPH<SM590000> CBU for more (optional) SAPs 

When CBU for CP is added within the same capacity setting range (indicated by the model capacity indicator) as the currently assigned PUs, the total number of active PUs (the sum of all assigned CPs, IFLs, ICFs, zIIPs, and optional SAPs) plus the number of CBUs cannot exceed the total number of PUs that are available in the system. 

When CBU for CP capacity is acquired by switching from one capacity setting to another, no more CBUs can be requested than the total number of PUs available for that capacity setting. 

## CBU and granular capacity 

When CBU for CP is ordered, it replaces lost capacity for disaster recovery. Specialty engines (ICFs, IFLs, and zIIPs) always run at full capacity, and when running as a CBU to replace lost capacity for disaster recovery. 

When you order CBU, specify the maximum number of CPs, ICFs, IFLs, zIIPs, and SAPs to be activated for disaster recovery. If a disaster occurs, you decide how many of each of the contracted CBUs of any type to activate. The CBU rights are registered in one or more records in the CPC. Up to eight records can be active, which can contain various CBU activation variations that apply to the installation. 

The number of CBU test activations that you can run for no extra fee in each CBU record is now determined by the number of years that are purchased with the CBU record. For example, a three-year CBU record includes three test activations, as compared to a one-year CBU record that has one test activation. 

You can increase the number of tests up to a maximum of 15 for each CBU record. The real activation of CBU lasts up to 90 days with a grace period of two days to prevent sudden deactivation when the 90-day period expires. The contract duration can be set 1 - 5 years. 

The CBU record describes the following properties that are related to the CBU: 

GLYPH<SM590000> Number of CP CBUs that are allowed to be activated 

GLYPH<SM590000> Number of IFL CBUs that are allowed to be activated 

GLYPH<SM590000> Number of ICF CBUs that are allowed to be activated 

GLYPH<SM590000> Number of zIIP CBUs that are allowed to be activated 

GLYPH<SM590000> Number of SAP CBUs that are allowed to be activated 

GLYPH<SM590000> Number of extra CBU tests that are allowed for this CBU record 

GLYPH<SM590000> Number of total CBU years ordered (duration of the contract) 

GLYPH<SM590000> Expiration date of the CBU contract 

