United States Patent (19) 11 Patent Number: 5,802,354 Kubala Et Al

IIIUSOO5802354A United States Patent (19) 11 Patent Number: 5,802,354 Kubala et al. 45 Date of Patent: Sep. 1, 1998 54 SESSESSEEogical :::::: y: a G. et al. ................... 395/551 PARTITIONS OF A PARTITIONED OTHER PUBLICATIONS NFORMATION HANDLING SYSTEM TO A TEST DATESOURCE "Enterprise Systems Architecture/390 Principles of Opera tion' IBM Publication, SA22-7201-02, Dec. 1994. (75) Inventors: JeffreyB. Mathias, P. Kubala, Vestal; Poughguag;Ira G. Siegel, Thomas New ocessor RResource/Systems C is S t sManager Planninging Uu1Guide” Paltz; David E. Whitney, IBM Publication, GA22-7236-01, Sep. 1996. Poughkeepsie, all of N.Y. Primary Examiner Thomas M. Heckler 73) Assignee: International Business Machines Attorney; Agent, or Firm-W. A. Kinnaman, Jr. Corporation. Armonk, N.Y. 57) ABSTRACT (21) Appl. No.: 871,429 A method and apparatus for synchronizing selected logical o partitions of a partitioned information handling system to a 22 Filed: Jun. 9, 1997 test datesource. A system operator is presented with a 6 display panel in which the operator may specify a set of test 2. 4 to spees ope-woo was seeds Pawa as aposuo Xu Pow Ge.K. partitions and a test clock value. Each partition designated as (58 Field of search an a wo be 44 440 x and see395551 555 a test partition is synchronized to the test clock value upon being newly activated, while production partitions are syn 395/200.78 chronized to a production clock value. The first test partition to be newly activated is synchronized to the test clock value 56) References Cited by calculating the difference between the test clock value U.S. PATENT DOCUMENTS and a host clock value and storing the difference as an epoch offset for that partition. Each subsequently activated test 4.843,541 6/1989 Bean et al.. partition is synchronized to the test clock value by copying 5,410,655 4/1995 Greenfield et al.. the epoch offset of the previously activated test partition. 5561809 10/1996 Elko et al.. 5.564.040 10/1996 Kubala. 5,564,903 10/1996 Eccles et al., 20 Claims, 4 Drawing Sheets CENTRAL PROCESSOR COMPLEX -104 122 122 122 122 LOGICAL LOGICAL LOGICAL LOGICAL CP CP CP CP 124 124 124 124 LP CLOCK LP CLOCK LP CLOCK LP CLOCK EPOCH OFFSE EPOCH OFFSET EPOCH OFFSET | EPOCH OFFSET 126 126 26 126 14 LP MANAGER TO ETR HOST CLOCK U.S. Patent Sep. 1, 1998 Sheet 1 of 4 5,802,354 CENTRAL 104 PROCESSOR COMPLEX CENTRAL EXTERNAL CENTRAL 104 PROCESSOR TIME PROCESSOR COMPLEX REFERENCE COMPLEX CENTRAL PROCESSOR COMPLEX 112 SUPPORT ELEMENT STORAGECENTRAL : 116 OPERATOR CONSOLE aropa m - e - - P en w an wo 110 CENTRAL PROCESSOR COMPLEX FIG.2 U.S. Patent 5,802,354 U.S. Patent Sep. 1, 1998 Sheet 3 of 4 5,802,354 [TER][?N?JIESÈ][EWS] LlaeZ07 U.S. Patent Sep. 1, 1998 Sheet 4 of 4 5,802,354 LP ACTIVATION 5O2 1 500 ANY OTHER LP ACTIVATED ? STORE HOST CLOCK VALUE 510 COPY EPOCH OFFSET CALCULATE EPOCH OF AL READY ACTIVATED OFFSET FOR PARTITION PARTITION SAVE CALCULATED EPOCH OFFSET 5,802,354 1. 2 to perform year 2000 testing in a logically partitioned METHOD AND APPARATUS FOR environment. Currently, in a partitioned S/390 central pro SYNCHRONIZING SELECTED LOGICAL cessor complex, each logical partition has its own logical PARTITIONS OF A PARTTONED partition clock together with an epoch offset indicating the NFORMATION HANDLING SYSTEM TO A difference between the logical partition clock and a host TEST DATESOURCE clock. This is described in the commonly owned application BACKGROUND OF THE INVENTION of B. A. Glendening et al., Ser. No. 08/168.281, filed Dec. 1. Field of the Invention 15, 1993, now U.S. Pat. No. 5.636,373, and incorporated This invention relates to a method and apparatus for herein by reference. By suitable setting of its epoch offset, synchronizing selected logical partitions of a partitioned 10 a particular partition may be synchronized to a test clock information handling system to a test clock value while value, e.g., for year 2000 testing, while the production allowing production partitions in the same central processor partitions may be synchronized to an actual clock value. complex to remain synchronized to a production clock While a single logical partition may thus be synchronized value. to a test clock value, currently an operator must use an entire 15 central processor complex to do year 2000 testing of a 2. Description of the Related Art multi-member "sysplex" (i.e., containing multiple logical The so-called year 2000 date problem has received much partitions). This is done in one of two ways in S/390 attention in the popular and trade press in recent years. environments. For a central processor complex that does not Basically, this problem results from the fact that, in order to have an external time reference (ETR) attached, the operator save storage space, many early software programs encoded 2 sets the time-of-day (TOD) clock of an attached support four-digit date fields with the last two digits only, so that the element ahead, does a power-on reset into logically parti year 1997, for example, would be encoded as the binary tioned mode, and uses the simulated ETR support of each equivalent of 97 (with the century being assumed) rather logical partition operating system (e.g., the SIMETRID than as the binary equivalent of 1997. Considerable effort support of OS/390 and MVS/ESA). For a central processor has been expended in recent years in addressing the date 25 complex that does have a real external time reference, the problem in legacy software, usually by replacing two-digit external time reference is set ahead. Neither of these year references with four-digit year references that fully alternatives, however, provides an environment where a capture century information. Because of the erratic nature of production system can operate alongside a multi-member early source documentation, revising date formats is a test sysplex that has a different time/date. time-consuming, error-prone activity. Software programs 30 that have retrofitted to eliminate the year 2000 date problem SUMMARY OF THE INVENTION must therefore be extensively tested to identify any residual The invention is directed to a method and apparatus for date problems, often by using a test datesource to simulate synchronizing selected logical partitions of a partitioned a post-millennium environment. information handling system to a test datesource. In accor One system platform that has been the focus of much year 35 dance with the invention, a system operator is presented with 2000 software retrofitting has been the IBM6) System/3908) a display panel in which the operator may specify a set of (S/3908) platform, owing to the considerable amount of test partitions making up a test sysplex, together with a software that has been created over the years for that starting test clock value. or datesource. The test clock value platform and its predecessors System/360TM and System/ may be selected for year 2000 testing and may differ from 370TM (S/370TM). the production clock value to which the non-test Many S/390 hardware machines operate in what is known (production) partitions are synchronized. Each partition des as logically partitioned (LPAR) mode. Logically partitioned ignated as a test partition is synchronized to the test clock computer systems are well known in the art and are upon its next activation, while production partitions are described in U.S. Pat. No. 4,564,903 (Guyette et al.), U.S. synchronized to a production clock as in a conventional Pat. No. 4,843,541 (Bean et al.), and U.S. Pat. No. 5564040 45 (Kubala), incorporated herein by reference. Commercial configuration. embodiments of logically partitioned systems include IBM The first test partition to be newly activated is synchro S/390 processors with the Processor Resource/Systems nized to the starting test clock value entered by the system Managers (PRISMTM) feature and described, for example, in operator. Each subsequently activated test partition, on the the IBM publication Processor Resource/Systems Manager other hand, is synchronized to the current clock value of the Planning Guide, GA22-7236-00, September 1996, incorpo previously activated test partition, which has meanwhile rated herein by reference. advanced from the starting value entered by the system Logical partitioning allows the establishment of a plural operator. As a result, all of the test partitions are synchro ity of system images within a single physical central pro nized to a common test clock value, allowing them to cessor complex (CPC). Each system image is capable of 55 interact as a true sysplex. In effect, the test partitions make operating as if it were a separate computer system. That is, up a virtual sysplex with a time and date other than that of each logical partition can be independently reset, initially the production sysplex. loaded with an operating system that may be different for BRIEF DESCRIPTION OF THE DRAWINGS each logical partition, and operate with different software programs using different input/output (I/O) devices. Logical FIG. 1 is a schematic block diagram of a computer system partitioning is in common use today because it provides its complex incorporating the present invention. users with flexibility to change the number of logical par FIG. 2 is a schematic block diagram of a particular central titions in use and the amount of physical system resources processor complex of the system complex of FIG. 1, show assigned to each partition, in some cases while the entire ing its principal hardware components. central processor complex continues to operate. 65 FIG.

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