Patent application number | Description | Published |
20080256312 | APPARATUS AND METHOD TO DETECT AND REPAIR A BROKEN DATASET - A method is disclosed to detect and repair a broken dataset. The method creates and maintains a backup log and an update log for a dataset. If the method finds a dataset structural error, then the method deletes the corrupted dataset, obtains the most current backup copy of the dataset, obtains all dataset updates made after the most current backup copy of the dataset was saved, and generates a recovered dataset using the most current backup and the dataset updates. | 10-16-2008 |
20090077554 | APPARATUS, SYSTEM, AND METHOD FOR DYNAMIC ADDRESS TRACKING - An apparatus, system, and method are disclosed for dynamic address tracking. A token module creates a token for a job that accesses data in a storage system comprising a plurality of storage devices. The token comprises a job name. The job is a batch job. A storage module stores location information for the data accessed by the job in a token table. The location information is indexed by the token. In addition, the location information includes an input/output device name, an address space, a data set name, and a storage device name. A communication module receives a diagnostic command comprising the job name. The token module reconstructs the token using the job name. The storage module retrieves the location information indexed by the token in response to the diagnostic command. | 03-19-2009 |
20090222599 | APPARATUS, SYSTEM, AND METHOD FOR ENQUEUE PRIORITIZATION - An apparatus, system, and method are disclosed for enqueue prioritization. The apparatus for enqueue prioritization is provided with a plurality of modules configured to functionally execute the necessary steps of anticipating a need to access a computing resource, generating a dummy request, the dummy request configured to hold a place for an actual request in a queue of requests to access the computing resource, and generating an actual request to access the computing resource, wherein the actual request is configured to replace the dummy request in the queue. These modules in the described embodiments include a forecast module, a dummy generator, and a request generator. | 09-03-2009 |
20090222600 | APPARATUS, SYSTEM, AND METHOD FOR ENQUEUE PRIORITIZATION - An apparatus, system, and method are disclosed for enqueue prioritization. The apparatus for enqueue prioritization is provided with a plurality of modules configured to functionally execute the steps of holding one or more queued requests in a queue, sorting the queued requests according to a first priority identifier associated with each of the queued requests, and assigning a second priority identifier to a delayed request in response to a determination that the delayed request has resided in the queue for a predetermined length of time, wherein the second priority identifier indicates a higher priority than the first priority identifier indicates. These modules in the described embodiments include a queue module, a sorting module, and a reassignment module. | 09-03-2009 |
20090259794 | SERVICEABILITY LEVEL INDICATOR PROCESSING FOR STORAGE ALTERATION - A method, system, and computer program product for implementing Serviceability Level Indicator Processing (SLIPs) for storage alterations in a computer system is provided. A plurality of storage release requests is analyzed to identify an address monitored by a storage alteration slip. Upon identification of the address, the storage alteration slip is disabled and an initialization slip is re-enabled. | 10-15-2009 |
20090276592 | BACKUP COPY ENHANCEMENTS TO REDUCE PRIMARY VERSION ACCESS - A method, system, and computer program product for performing a backup operation in a computing environment is provided. A dataset corresponding to a backup copy is examined to determine if the dataset has changed from a previous backup operation. If the dataset has not changed, a backup inventory registry is consulted to determine a current version of a backup copy. The current version is one of a plurality of available versions. The backup operation is performed using the current version of the backup copy. | 11-05-2009 |
20100005126 | RECORD LEVEL FUZZY BACKUP - A method, system, and computer program product for performing a backup operation in a computing environment is provided. A list of keys identifying a plurality of locked records is created at a start of the backup operation. If a first locked record of the plurality of locked records is obtained during the backup operation, a first key identifying the first locked record is added to the list of keys. At a completion of the backup operation, if a second locked record of the plurality of locked records was not moved during the backup operation, a second key identifying the second locked record from the list of keys is dropped. The list of keys is written to a log file as in-flight updates. The in-flight updates are reprocessed through the backup operation using the log file. | 01-07-2010 |
20100005316 | BRANCH TRACE METHODOLOGY - Method, system, and computer program product embodiments for performing a branch trace operation on a computer system of an end user are provided. An encrypted mapping macro is provided to the end user to be made operational on the computer system. A trace program is provided to the end user. The end user executes the trace program on the computer system as a diagnostic tool. The trace program is adapted for decrypting the encrypted mapping macro, determining a storage offset location of a branch instruction; checking the storage offset location for an identifying constant, cross referencing the identifying constant with an entry in the decrypted mapping macro to identify a branch triggering bit and diagnostic information associated with the branch instruction, and returning the branch triggering bit and diagnostic information, the branch triggering bit and diagnostic information provided to a coder. | 01-07-2010 |
20100023725 | GENERATION AND UPDATE OF STORAGE GROUPS CONSTRUCTED FROM STORAGE DEVICES DISTRIBUTED IN STORAGE SUBSYSTEMS - A plurality of storage subsystems and a plurality of storage devices are maintained, and wherein each storage subsystem includes at least one storage device of the plurality of storage devices. A plurality of storage groups is generated, wherein each storage group includes one or more storage devices selected from the plurality of storage devices, and wherein the one or more storage devices selected in each storage group are included in at least two different storage subsystems. The plurality of storage groups is adjusted based on: (a) usage statistics of the data, wherein the usage statistics are stored in a log file; and (b) properties and organization of the data stored in a plurality of data structures. | 01-28-2010 |
20100023803 | TRANSITIONAL REPLACEMENT OF OPERATIONS PERFORMED BY A CENTRAL HUB - A central hub is coupled to a plurality of computational devices. The central hub stores a data structure that grants locks for accessing common data stored at the central hub, wherein the common data is shared by the plurality of computational devices. Each computational device maintains locally those locks that are held by the computational device in the data structure stored at the central hub. In response to a failure of the data structure stored at the central hub, a selected computational device of the plurality of computational devices is determined to be a manager system. Other computational devices besides the manager system communicate to the manager system all locks held by the other computational devices in the data structure stored at the central hub. The data structure and the common data are generated and stored at the manager system. Transactions are performed with respect to the data structure stored at the manager system, until the data structure stored at the central hub is operational. | 01-28-2010 |
20100030828 | DETERMINATION OF INDEX BLOCK SIZE AND DATA BLOCK SIZE IN DATA SETS - A plurality of data sets is maintained, wherein each data set comprises an index block and a plurality of data blocks. An index block size is determined for redefining the plurality of data sets, based on an amount of space left unused in index blocks of the plurality of data sets, wherein for determining the index block size greater weight is provided to those index blocks with lesser unused space in comparison to those index blocks with greater unused space. A data block size is determined based on whether the plurality of data blocks is used more frequently for direct processing or used more frequently for sequential processing. | 02-04-2010 |
20100042663 | APPARATUS AND METHOD TO OPTIMIZE THE AVAILABLE STORAGE CAPACITY OF A PLURALITY OF SEQUENTIAL DATA STORAGE MEDIA DISPOSED IN A DATA STORAGE SYSTEM - A method to optimize use of available storage capacity of a plurality of sequential data storage media, wherein the method provides (M) sequential data storage media each comprising a plurality of blockids, where the (i)th sequential data storage medium comprises an (i)th available storage capacity, and where (M) is greater than or equal to 2, and where (i) is greater than or equal to 1 and less than or equal to (M). The method then receives source data comprising a plurality of segments, determines a quantum of data to store, determines if the quantum of data to store is substantially equal to an (i)th available storage capacity. If the quantum of data to store is substantially equal an (i)th available storage capacity, then the method writes the source data to an (i)th sequential data storage medium. | 02-18-2010 |
20100077255 | CATALOG RECOVERY THROUGH SYSTEM MANAGEMENT FACILITIES REVERSE TRANSVERSAL - A method for forward recovery of a catalog of a data storage system, comprising providing a recovery catalog and SMF records. In reverse chronological order, the (i)th entry of the record is checked for a data set change command. If none, the next entry is examined. Otherwise, the (j)th data set is identified and checked for inclusion in the recovery catalog. If it already is, the next entry is selected. If not, a data set location record is added. This process is repeated for each entry in the SMF record. Next, a (h)th data set on the (k)th volume is selected and checked for inclusion in the recovery catalog. If that (h)th data set has been added to the recovery catalog, a next data set is selected. Otherwise, a data set location record for the (h)th data set is added. The process is repeated for each data set on each volume. | 03-25-2010 |
20100083052 | Apparatus, System, and Method for Multi-Address Space Tracing - An apparatus, system, and method are disclosed for multi-address space tracing. A trigger module establishes a trigger event with a trace level. The trigger event occurs in at least a first address space of a plurality of address spaces. The trace level defines trace data to be stored from the plurality of address spaces. A monitor monitors messages communicated within and between the plurality of address spaces. A detection module detects the trigger event. A log module logs the trace data from the plurality of address spaces defined by the trace level in response to detecting the trigger event. | 04-01-2010 |
20100094811 | Apparatus, System, and Method for Virtual Storage Access Method Volume Data Set Recovery - An apparatus, system, and method are disclosed for Virtual Storage Access (VSAM) Volume Data Set (VVDS) recovery. A store module stores a data set name and data set characteristics for a data set in a recovery table when the data set is defined under a Z/OS® operating system. The recovery table indexed by the data set name. A retrieve module retrieves a Z/OS® Volume Table of Contents (VTOC) entry indexed by the data set name. In addition, the retrieve module retrieves the data set characteristics from the recovery table using the data set name. A recover module combines the data set characteristics and the VTOC entry to recover a Z/OS® VVDS entry. | 04-15-2010 |
20100180093 | RAPID DEFRAGMENTATION OF STORAGE VOLUMES - Various embodiments for rapid defragmentation of storage volumes in a computing environment are provided. A plurality of source data sets is copied from the fragmented storage volume to a plurality of target data sets on an additional storage volume. The plurality of source data sets is placed on the additional storage volume as the plurality of target data sets in an unfragmented order. A first volume serial number (VOLSER) of the fragmented storage volume is swapped with a second VOLSER of the additional storage volume. The fragmented storage volume is varied offline, and the additional storage volume is varied online. The computing environment recognizes the additional storage volume having the plurality of target data sets placed in the unfragmented order. | 07-15-2010 |
20100180156 | INTELLIGENT DUMP SUPPRESSION - Various embodiments for intelligent dump suppression in a computing environment following an error are provided. A plurality of historical information is considered in view of a current alert level to generate an output decision. The current alert level is one of an available plurality of alert levels configurable by a user. The current alert level is selectable by the user for a predetermined data collection restrictiveness. Data capture is performed according to the output decision. | 07-15-2010 |
20100180262 | OVERLAY IDENTIFICATION OF DATA PROCESSING TARGET STRUCTURE - A method, system, and computer program product for identifying an overlay of a data processing target structure in a computing environment is provided. At least one of examining a mapping macro for the target structure with a set of valid ranges, comparing the set of valid ranges with the target structure to identify a string of at least one first invalid value and a last invalid value and locate invalid regions of the target structure, and examining executable code associated with the target structure, comparing at least one unchanged module against at least one additional module exhibiting an overlay characteristic to identify the string of the at least one first invalid value and the last invalid value and locate invalid regions of the target structure, is performed. | 07-15-2010 |
20100185589 | DISASTER RECOVERY DATA SYNC - Various embodiments for failure recovery in a computing environment following a data restoration are provided. A catalog locate is performed for each of a plurality of data sets on a base catalog structure (BCS), identifying a plurality of BCS entries. If a first BCS entry is cataloged incorrectly, the first BCS entry is designated to be re-cataloged. The plurality of BCS entries is compared with a plurality of volume table of contents and a plurality of VSAM volume data set (VTOC/VVDS) entries. If a second BCS entry found in the plurality of BCS entries is not found in the plurality of VTOC/VVDS entries, and the second BCS entry indicates that a data set associated with the second BCS entry is located on a volume, an attempt is made to vary on the volume. If the volume cannot be varied on, a request is created to restore the volume. | 07-22-2010 |
20100185697 | MAINTAINING A DATA STRUCTURE WITH DATA SET NAMES AND POINTERS TO A PLURALITY OF CATALOGS - A plurality of catalogs are maintained, and wherein each catalog of the plurality of catalogs includes data sets and attributes of the data sets. An indication that a new data set is to be defined is received. A selected catalog is determined from the plurality of catalogs, wherein the selected catalog is suitable for including the new data set and attributes of the new data set. An entry that indicates a data set name corresponding to the new data set and an index to the selected catalog is inserted in a group table. | 07-22-2010 |
20100185829 | EXTENT CONSOLIDATION AND STORAGE GROUP ALLOCATION - Data is added to a data set to cause a growth in size of the data set, wherein the data set belongs to a storage group, and wherein the data set is comprised of extents. The data set is included into a new storage group, in response to determining that the growth in the size of the data set has caused a predetermined threshold for a size limit of the storage group to be exceeded. The extents of the data set are restructured to satisfy a predetermined condition on the extents of the data set, in response to determining that the growth in the size of the data set has caused the predetermined condition on the extents included in the data set to be not satisfied. | 07-22-2010 |
20100191738 | APPARATUS, SYSTEM, AND METHOD FOR MODIFYING DATA SET NAMES - An apparatus, system, and method are disclosed for modifying data set names. A communication module receives a data set name as an index of a catalog entry for a catalog. The data set name comprises at least two qualifiers. A modification module modifies at least one data set name qualifier using a naming algorithm, wherein an alias qualifier is not modified. A store module stores the catalog entry indexed with the modified data set name in order to optimize the location of that entry within the catalog. | 07-29-2010 |
20100217930 | MANAGING PROCESSING SYSTEMS ACCESS TO CONTROL BLOCKS PROVIDING INFORMATION ON STORAGE RESOURCES - Provided are a method, system, and article of manufacture to manage storage resources in a storage system. Requests by processing systems are received for access to a control block providing information on an address assigned to one of the storage resources to access. A token is generated for each processing system requesting the control block uniquely identifying the processing system and the control block. The processing systems are provided copies of the requested control blocks to use to access the storage resource. A request is received to modify one of the control blocks for one of the storage resources. A determination is made as to whether at least one of the tokens was generated for the control block to modify. At least one processing system associated with the determined at least one token is provided a copy of the modified control block to use to access the storage resource associated with the control block. | 08-26-2010 |
20100228708 | ALLOCATING DATA SETS TO A CONTAINER DATA SET - Provided are a method, system, and program for allocating data sets to a container data set. A container data set is allocated in a storage system. An entry is included in a file allocation catalog for the allocated container data set indicating an address range of data allocated to the container data set, wherein the file allocation catalog maps data sets to address ranges in the storage system. A virtual file allocation catalog for the container data set is generated. A request is received to allocate a data set. A determination is made as to whether the data set to allocate has a size less than a threshold size. An entry is included in the virtual file allocation catalog to allocate the data set in the address range of the container data set in response to determining that the data set to allocate size is less than the threshold size. | 09-09-2010 |
20100228898 | APPARATUS, SYSTEM, AND METHOD FOR REAL TIME JOB-SPECIFIC BUFFER ALLOCATION - An apparatus, system, and method are disclosed for dynamically allocating buffers during the execution of a job. A plan module sets a buffer allocation plan for the job using data access history that contains information about the number and nature of data access events in past executions of the same job. A buffer module allocates buffers during the execution of the job, and alters the buffer allocation to improve performance for direct access events for those portions of the job that the buffer allocation plan indicates have historically included predominantly direct access events. The buffer module alters the buffer allocation to improve performance for sequential access events for those portions of the job that the buffer allocation plan indicates have historically included predominantly sequential access events. A history module then collects data access information about the current execution and adds that information to the data access history. | 09-09-2010 |
20100251214 | APPARATUS, SYSTEM, AND METHOD FOR DYNAMIC MODULE FLOW ANALYSIS - An apparatus, system, and method are disclosed for analyzing code paths. In one embodiment, a starting point for one or more code paths within a listing of code is specified. The starting point may include code from which one or more code paths flow. An ending point is also specified for one or more code paths within the code, wherein the ending point includes code that is reachable via one or more of the code paths flowing from the starting point. Each code path flowing from the starting point to the ending point is determined by analyzing the listing of code without execution of the code. Information about the determined code paths is provided to a user. | 09-30-2010 |
20100281000 | METHOD AND APPARATUS FOR PARTIAL DATA SET RECOVERY - A method for data recovery of a data set migrated from a first storage media to a second storage media, where the data set includes a header record and multiple control records interleaved with corresponding data blocks. The header record is examined to identify a number of control records and data blocks comprising the data set. Next, the control records and data blocks are examined in order, starting with an initial data block, until a first data block is identified due to its failure to match the attribute included in the associated control record. Then the control records and data blocks are examined in reverse order, starting with a last data block, until a second data block is identified due to its failure to match an attribute included in the associated control record. Lastly, each data block from the first data block to the second data block are set to a lost data value. | 11-04-2010 |
20100293354 | APPARATUS AND METHOD FOR MINIMIZING DATA STORAGE MEDIA FRAGMENTATION - A method of minimizing data storage medium fragmentation, wherein the method provides a data storage library comprising (N) data storage media, wherein (N) is greater than or equal to 1. The method establishes a threshold fragmentation index, and determines, for each value of (i), an actual fragmentation index for an (i)th data storage medium, wherein (i) is greater than or equal to 1 and less than or equal to (N). The method receives a data set from a host computer in communication with the data storage library, and writes the data set to an (i)th data storage medium based upon an (i)th actual fragmentation index. | 11-18-2010 |
20110258485 | TRANSITIONAL REPLACEMENT OF OPERATIONS PERFORMED BY A CENTRAL HUB - A central hub is coupled to a plurality of computational devices. The central hub stores a data structure that grants locks for accessing common data stored at the central hub, wherein the common data is shared by the plurality of computational devices. Each computational device maintains locally those locks that are held by the computational device in the data structure stored at the central hub. In response to a failure of the data structure stored at the central hub, a selected computational device of the plurality of computational devices is determined to be a manager system. Other computational devices besides the manager system communicate to the manager system all locks held by the other computational devices in the data structure stored at the central hub. The data structure and the common data are generated and stored at the manager system. Transactions are performed with respect to the data structure stored at the manager system, until the data structure stored at the central hub is operational. | 10-20-2011 |
20110307745 | UPDATING CLASS ASSIGNMENTS FOR DATA SETS DURING A RECALL OPERATION - Provided are a computer program product, system and method for updating class assignments for data sets during a recall operation in a storage environment having a plurality of storage devices. Information on a data set is processed to determine at least one current attribute of the data set. A determination is made as to whether the determined at least one current attribute satisfies a criteria. Indication is made in a catalog to change a class associated with the data set in response to determining that the at least one current attribute satisfies the criteria, wherein the class is used to determine how to manage the data set. The data set is migrated from a first storage to a second storage. A recall operation is initiated to recall the data set from the second storage. In response to the recall operation and determining that the catalog indicates to change the class associated with the data set, the catalog is processed to determine whether to change the class for the data set from a first class to a second class and a management operation is performed on the data set to conform the data set to the second class when recalling the data set. | 12-15-2011 |
20120011169 | PROCESSING OF SPLITS OF CONTROL AREAS AND CONTROL INTERVALS - A data structure maintained in a computational device stores how many control areas splits have occurred to store a data set, wherein each control area split causes an addition of a single new control area. A command is received to add a new data record to the data set. A determination is made as to whether adding the new data record to the data set will result in a threshold for control area splits to be exceeded. In response to determining that adding the new data record to the data set will result in the threshold for control area splits to be exceeded, creating at least two new control areas in addition to continuing to use one existing control area for storing the data set. | 01-12-2012 |
20120096235 | Allocation of Storage Space for Critical Data Sets - Described are embodiments of an invention for allocating storage space in a storage system for critical data sets. The computing environment includes at least one server including a processor and memory. The server is coupled to storage. The memory further includes a storage manager including an allocation module and an alert module. The storage manager defines a common area for storing non-critical data sets and critical data sets in the storage group. The storage manager also defines a critical reserve area for storing only critical data sets in the first storage group. A predefined percentage of available storage space is reserved for the critical reserve area. The predefined percentage of available space is determined by comparing the available storage space within the critical reserve area to the storage space in the storage group. Upon allocating additional storage to the storage group, the allocation module allocates an amount of the additional storage space to the critical reserve area such that the predefined percentage of available storage space is maintained in the critical reserve area. | 04-19-2012 |
20120203784 | MAINTAINING A DATA STRUCTURE WITH DATA SET NAMES AND POINTERS TO A PLURALITY OF CATALOGS - A plurality of catalogs are maintained, and wherein each catalog of the plurality of catalogs includes data sets and attributes of the data sets. An indication that a new data set is to be defined is received. A selected catalog is determined from the plurality of catalogs, wherein the selected catalog is suitable for including the new data set and attributes of the new data set. An entry that indicates a data set name corresponding to the new data set and an index to the selected catalog is inserted in a group table. | 08-09-2012 |
20120265790 | PROCESSING OF SPLITS OF CONTROL AREAS AND CONTROL INTERVALS - A data structure maintained in a computational device stores how many control areas splits have occurred to store a data set, wherein each control area split causes an addition of a single new control area. A command is received to add a new data record to the data set. A determination is made as to whether adding the new data record to the data set will result in a threshold for control area splits to be exceeded. In response to determining that adding the new data record to the data set will result in the threshold for control area splits to be exceeded, creating at least two new control areas in addition to continuing to use one existing control area for storing the data set. | 10-18-2012 |
20120271861 | PROCESSING OF SPLITS OF CONTROL AREAS AND CONTROL INTERVALS - A data structure maintained in a computational device stores how many control areas splits have occurred to store a data set, wherein each control area split causes an addition of a single new control area. A command is received to add a new data record to the data set. A determination is made as to whether adding the new data record to the data set will result in a threshold for control area splits to be exceeded. In response to determining that adding the new data record to the data set will result in the threshold for control area splits to be exceeded, creating at least two new control areas in addition to continuing to use one existing control area for storing the data set. | 10-25-2012 |
20120278367 | PROCESSING OF SPLITS OF CONTROL AREAS AND CONTROL INTERVALS - A data structure maintained in a computational device stores how many control areas splits have occurred to store a data set, wherein each control area split causes an addition of a single new control area. A command is received to add a new data record to the data set. A determination is made as to whether adding the new data record to the data set will result in a threshold for control area splits to be exceeded. In response to determining that adding the new data record to the data set will result in the threshold for control area splits to be exceeded, creating at least two new control areas in addition to continuing to use one existing control area for storing the data set. | 11-01-2012 |
20130007394 | REORGANIZATION OF A FRAGMENTED DIRECTORY OF A STORAGE DATA STRUCTURE COMPRISED OF THE FRAGMENTED DIRECTORY AND MEMBERS - A directory and members are allocated to store a data set, wherein the directory stores pointers to the members to allow data stored in the members to be accessed. The directory is expanded to accommodate an expansion of the data set, causing the directory to be stored in non-contiguous pages and becoming fragmented. A computational device determines that a threshold that measures a level of fragmentation of the directory relative to an amount of storage allocated for the data set has been exceeded. The computational device reorganizes the fragmented directory, into a reorganized directory that is stored in contiguous pages at the end of the data set, in response to determining that the threshold has been exceeded. | 01-03-2013 |
20130218834 | DYNAMIC VVDS EXPANSION - A method for addressing an out-of-space condition for a VSAM Volume Data Set (VVDS) includes detecting an out-of-space condition in a VVDS on a volume. The method creates, in response to the out-of-space condition, a new VVDS on the volume without adding a record to the old VVDS (e.g., by bypassing “catalog services”). The new VVDS is assigned a temporary name. The method then copies records from the old VVDS to the new VVDS. The method may then rename the old VVDS to a temporary name and rename the new VVDS to the original name of the old VVDS. The old VVDS may then be deleted. Alternatively, instead of renaming the old VVDS to a temporary name, the old VVDS may be deleted. The new VVDS may then be renamed to the original name of the old VVDS. A corresponding apparatus and computer program product are also described. | 08-22-2013 |
20130219371 | TIME-BASED TRACE FACILITY - Method, system, and computer program product embodiments of a time-based trace facility for facilitating software debugging without interfering with the run-time behavior, performance or resource usage of the traced software are provided. The trace facility resides in a different address space than the target address space and uses different time-slices of CPU resources to execute the instructions in the address spaces. The trace facility uses a cross-memory mode to read the state data from the target address space in accordance with a time schedule. The trace facility writes the state data to a trace area, which may be located in either the target or trace address spaces or external storage. With this approach, the trace facility can read a large amount of state data frequently to construct the type of historical record needed to analysis run-time behavior, performance and resource usage. | 08-22-2013 |
20130275670 | MULTIPLE ENHANCED CATALOG SHARING (ECS) CACHE STRUCTURE FOR SHARING CATALOGS IN A MULTIPROCESSOR SYSTEM - Various method and system embodiments for facilitating catalog sharing in multiprocessor systems use multiple ECS cache structures to which catalogs are assigned based on an attribute such as SMS storage class or a high level qualifier (HLQ) (e.g. an N-to-1 mapping) or each individual catalog (e.g. a 1-to-1 mapping). When maintenance is performed on an ECS shared catalog, the multiple ECS cache structure requires only those catalogs associated with a particular ECS cache structure be disconnected. Any catalogs in the structure that are not involved in or affected by the maintenance may be temporarily or permanently moved to a different ECS cache structure. As a result, VVDS sharing is only required for those catalogs on which maintenance is being performed or that remain associated with that ECS cache structure during maintenance. This reduces I/O activity to the DASD, and results in a significant overall performance improvement. | 10-17-2013 |