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Virtual Timed Power On a LPAR system

IP.com Disclosure Number: IPCOM000010320D
Original Publication Date: 2002-Nov-20
Included in the Prior Art Database: 2002-Nov-20
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Abstract

Given an LPAR (Logical PARtitioned) system with a Service Processor (SP) that only has one Watch Dog Timer (WDT), one battery-backed Real Time Clock (RTC), and a secondary counter (SC), that supports TPO functionality, and that each LPAR partition keeps its own local time by a virtualized clock subsystem. TPO allows a system to power on automatically at a specific date and time.The implementation detailed in this document can be applied to provide Time the Power On (TPO) capabilities on LPAR systems above described. This will allow each LPAR partition to perceive the WDT facility as its own, so that each partition can achieve TPO independently. The advantage of this method is the savings of additional hardware (i.e. RTC, WDT) for TPO to be supported.

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Virtual Timed Power On a LPAR system

To provide Time Power On (TPO) capabilities on LPAR systems. TPO allows a system to power on automatically at a specific date and time with multiple partitions running on the LPAR system.

Given that the LPAR system with a Service Processor (SP) that only has one Watch Dog Timer(WDT), one battery-backed Real Time Clock(RTC), and a secondary counter (SC), that supports TPO functionality on several partitions, and that each partition keeps its own local time by a virtualized clock subsystem, an implementation like the one detailed in this document can be applied.

This method will allow each LPAR partition to perceive the WDT facility as its own, so that each partition can achieve TPO independently. The advantages are the savings of additional hardware (i.e. RTC, WDT, SC) for TPO to be supported.

This solution proposes to store in NVRAM the TPO date/time parameters, and an offset value that represents the future state of the SC. The SP monitors the NVRAM entries per partition and determines when to power on either just a (1)LPAR partition or (2)the entire system plus a LPAR partition depending on the system state.

If the system is in the running state with more than one active partitions or the shutdown policy is set to only shutdown the partition and not the entire system, then TPO only applies to the partition and not the entire system. However, if the system has only one active partition or TPO is issued on multiple partitions and the shutdown policy is set to shutdown the system when the last active partitio...