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Dynamic Conversion of Central to/from Expanded Storage (aka Single Storage Pool)

IP.com Disclosure Number: IPCOM000199545D
Publication Date: 2010-Sep-08
Document File: 1 page(s) / 41K

Publishing Venue

The IP.com Prior Art Database


Prior to this invention, physical storage had to be allocated by the Processor Resource/Systems Manager (PR/SM) for eventual use by logical partitions as either central storage or expanded storage during the Initial Microcode Load (IML) and could not be dynamically changed. With this invention, all physical storage is dynamically designated as either central or expanded storage, thus eliminating the need for an IML to alter the allocation.

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Dynamic Conversion of Central to/from Expanded Storage (aka Single Storage Pool)

Prior to this invention, the allocation of physical storage as either central storage or expanded storage was done during the Initial Microcode Load (IML) by the Processor Resource/Systems Manager hypervisor (PR/SM hypervisor). Without this invention, a possibly non-optimum division of storage needed to be made to accommodate a range of logical partition definitions that typically vary from time-to-time. Once the allocation was done, the only way to change the allocation was to do another IML. This is disruptive in that all logical partitions must first be stopped and then the IML performed, and then the software reloaded into the logical partitions. The system is not performing useful work during this time, which could take several minutes. In addition, because this allocation had to be performed during an IML, there was no way to dynamically alter the amount of physical storage either, since there would be no way during the dynamic alteration of physical storage to change the existing allocation. Finally, the user had to actually make the allocation via a user interface selection. With the invention, the user no longer needs to make a selection at all, as PR/SM hypervisor automatically provides for the correct storage designation for any configuration of logical partitions as the need arises.

   At IML time, the physical storage is placed into a single storage pool of available memory where it is neither central nor expanded storage, but just free storage. At logical partition activation time, as well as other times such as attach central storage element, assign storage increment, and configure expanded storage element Service Call Logical Processor (SCLP) emulation, backing physical storage is taken from the single pool of storage. Hardware tables that control access...