International Business Machines Corporation

Stephen Merritt Branch

Patricia Driscoll Choi

Mark Edward Thomen

Michael Koester

Kevin L Miner

Harold Steven Huber

Sanjay Shyam

Savur Anand Rao

Edward H Daray, Jr

Victor Sheng-Jian Liang

In one general embodiment, a computer-implemented method includes initializing a storage volume, receiving a request to secure unallocated data within the storage volume, sending a bit map to a hardware portion of the storage volume, in response to receiving the request, identifying unallocated data within the hardware portion of the storage volume utilizing the bit map, and marking the unallocated data as read inhibited within the hardware portion of the storage volume.

Protecting unallocated data within a storage volume

A dynamic construct is associated with one or more operational parameters of one or more components of a storage management system, wherein a pointer to the construct is retained in metadata for the storage management system, the values of the construct are stored in a first repository separate from a second repository normally used to store the metadata for the storage management system. The value of the construct in the first repository is allowed to change dynamically at any point of time without affecting the metadata in the second repository. Thereafter, the value of the construct in the first repository is retrieved and used as the operational parameter, instead of a static value in the metadata in the second repository. This provides a level of indirection that allows the construct to be applied dynamically in the storage management system.

Method for specifying a dynamic construct in a storage management system

Provided are a method, system, and program for allocating physical storage units to a data set, wherein one or more extents of storage units are assigned to the data set. A request is received to allocate additional storage units to the data set and a determination is made of a range of available storage units to allocate to the data set in response to the request. A determination is made of one pre-existing extent allocated in the data set before receiving the request and of whether at least one storage unit in the determined range can be allocated to the determined pre-existing extent. At least one storage unit in the determined range is allocated to the determined pre-existing extent if the at least one storage unit can be allocated to the determined pre-existing extent.

Method, system, and program for allocating storage units to a data set

A method and system for sharing a catalog in a multiprocessor system is disclosed. The multiprocessor system includes a plurality of host systems. The method and system comprises storing a copy of an entire volume data record of the catalog in a processor. Thereafter, the method and system comprises reading sharing information of the catalog from the processor to the appropriate host system when the appropriate host system needs access to the catalog. For example, in a S/390 parallel processor system an enhanced catalog sharing system (ECS) is utilized in conjunction with the catalogs. In this type of system, a copy of the entire data VSAM volume record (VVR) for an ECS-active catalog is stored in a coupling facility processor. This processor is accessed using components of the S/390 product. When an ECS-active host system needs access to an ECS-active catalog, the sharing information is read in from the coupling facility processor instead of a DASD volume. If the shared catalog request involves an update to the ECS-active catalog, the (VVR) in the coupling facility is updated; no writes are performed to DASD for updates to the sharing subcell. By storing the sharing control data on a shared processor, the I/O operations and the disk lock outs are eliminated, dramatically decreasing elapsed time for a shared catalog request and increasing the availability of the disk device. This results in a significant performance improvement, with shared catalog performance approaching that of unshared catalogs.

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Morgan Hill, CA, United States of America

Stephen Merritt Branch