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GLYPH<SM590000> Extra zIIPs, which can be added by using the temporary boost capacity records (FC 9930 and FC 6802 on z15) 

If more logical zIIPs are available and configured in the LPAR profile (whether added by way of the temporary boost capacity record or other temporary capacity activation) while in the boost period, images bring more logical zIIP processors online to use the extra physical zIIP capacity. 

After the boost period ends, z/OS dispatching of work on CPs versus zIIPs returns to normal. 

Important:  These extra logical processors should be taken offline at the end of the boost period (either manually or by using automation), or they are taken offline automatically when the temporary boost record expires. 

The start and end of the boost period is signaled by way of a console message, ENF signal (84), and cutting an SMF record. Also, the start and end of boost period starts new SMF interval. A system command or PROC (IEABE) is provided to allow for early opt-out of the boost, if wanted. 

## System Recovery Boost using zIIP boost example 

Figure B-3 shows an example of recovery boost using zIIP capacity boost. 

<img src='content_image/982502.jpg'>

In this example, three LPARs are defined on the z15 model 703 with two zIIPs. Two zIIPs are shared between LPARy and LPARz. 

During normal operation, only zIIP eligible work is dispatched to the zIIPs. When LPARz enters a boost period, general-purpose work and zIIP eligible work might be dispatched to the zIIPs. 

When the boost period ends, only zIIPs-eligible work is dispatched to the zIIPs. 

