Abstract: 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.

Abstract: A method for addressing an out-of-space condition for a Virtual Storage Access Method (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.

Abstract: A method for addressing an out-of-space condition for a Virtual Storage Access Method (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.

Abstract: 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.

Abstract: A method for automatically optimizing an allocation amount for a data set includes receiving an extend request, specifying an allocation amount, for a data set in a storage pool. The method increments a counter in response to receiving the extend request. In the event the counter has reached a threshold value, the method automatically increases the allocation amount of the extend request, such as by multiplying the allocation amount by a multiplier. In the event the allocation amount is larger than a largest free extent in the storage pool, the method automatically decreases the allocation amount of the extend request to correspond to the largest available free extent. Such a method reduces or eliminates the chance that an extend request will fail, and reduces overhead associated with extending and consolidating extents. A corresponding apparatus and computer program product are also disclosed herein.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.