Digital computing apparatus and method for operating the same

Claim 3

The method of claim 1, wherein said storage devices are logical devices in a single physical storage device.

Claim 4

The method of claim 1, further comprising the steps of monitoring the actual access density of data sets stored in said first storage device; and responsive to the actual access density of-a given data set becoming substantially less than the access density of said first storage device, moving said given data set to another storage device.

Claim 5

The method of claim 1 comprising the steps of: calculating the access density of a data set to be allocated to a storage device as egual to the number of accesses per unit time to that data set divided bv the data set volume; calculating the access density of each of said plurality of storage devices attached to the system as equal to the number of accesses that a device can sustain per unit time divided by the data storage capacity of the device; allocating the data set to a storage device that has sufficient available space and a device access density most nearly matching and exceeding the access density of the data set being allocated; and continuously monitoring and recalculating the data set access density and reallocating the data set as required to maintain the data set on a device having the most nearlv matching access density.

Claim 6

The method of claim 1 including partitioning a single direct access storage device into a plurality of logical devices having different device characteristics matching the device performance required for a plurality of data sets, comprising the steps: selecting data sets to be stored on the single device, and calculating for each data set its access density; selecting data sets having access densities equal to or greater than the single device access density for assignment to a partition designated to support a high access density; setting the access density of the high access partition equal to the highest access density of the data sets assigned to the high access partition; selecting data sets having access densities less than the single device access density for assignment to a partition designated to support low access density; setting the access density of the low across partition equal to he highest access density of the data sots assigned to the low access partition; and partitioning the total capacity of the single device between high and low access partitions such that the high access partition contains sufficient volume to yield the required access density.

Claim 7

A method of claim 2 comprising the steps: calculating the access density of the physical storage device as equal to the total access per unit time sustainable by the device divided by the total storage capacity of the device; determining for each of a plurality of data sets to be stored on said physical storage device a data set access density equal to the total access per unit time to be made to that data set divided by the volume of data allocated to a data set; allocating the data sets to at least two groups based upon their access densities, and assigning to each group an access density value related to the access densities of the assigned data sets; partitioning the physical storage device into a plurality of logical devices of different access densities, where the sum of the access densities of the logical devices equals the access density of the storage device; and assigning each of said groups to a logical device on the basis of their respective access densities.

Claim 8

A method of claim 1 for operating a stored program digital computer to store and access data records from a plurality of data sets on a direct access storage device of the type having a plurality of concentric data storage cylinders, where a cylinder comprises one or more tracks, comprising the steps of: partitioning the storage device into a pluralitv of partitioned devices including a first partitioned device having at least first and second cylindrical parts and a second partitioned device including a third cylindrical part concentric with and contained within said first and second cylindrical parts; and storing in said first partitioned device data records in one or more data sets having lower access densities and in said second partitioned device data records in one or more data sets having higher access densities.

Claim 9

Digital computing apparatus for storing and accessing data records in a plurality of data sets, characterized by: direct access storage device means (20) having a plurality of concentric data storage cylinders, each cylinder comprising one or more tracks, for storing data signals; said storage device means further comprising first partitioned device means (42, 44) having at least first (42) and second (44) cylindrical parts and second partitioned device means (40) including a third cylindrical part concentric with and contained within said first and second cylindrical parts; means for determining the access densities of a plurality of data sets; and means for storing in said first partitioned device means data records in one or more data sets having lower access densities and in said second partitioned device means data records in one or more data sets having higher access densities.

Claim 10

Digital computing apparatus for storing and accessing data records in a plurality of data sets, characterized by: direct access storage device means (20) having a plurality of concentric data storage cylinders, each cylinder comprising one or more tracks, for storing data signals; said storage device means further comprising first partitioned device means (42, 44) having at least first (42) and second (44) cylindrical parts and second partitioned device means (40) including a third cylindrical part concentric with and contained within said first and second cylindrical parts; means for determining the access densities of a plurality of data sets; and means for storing in said first partitioned device means data records in one or more data sets having lower access densities and in said second partitioned device means data records in one or more data sets having higher access densities.

Claim 11

The apparatus of claim 8, further comprising: means for determining the device access density of said second partitioned device means; monitoring means for monitoring the actual access density of a data set as a function of time; means responsive to said monitoring means for removing from said second partitioned device means a data set having an actual access density which is substantially lower than the device access density.

Claim 12

The apparatus of claim 9, further comprising: means responsive to said monitoring means for moving from said first partitioned device means a data set having an actual access density which is substantially higher than the access density of the first partitioned device means.

Claim 13

The apparatus of claim 8, further comprising: means for storing as a stored access density a determined access density of a given data set assigned to said second partitioned device means; means for monitoring the actual access density of said given data set as a function of time; means, responsive to said actual access density of said given data set becoming substantially different from said determined access density, for substituting the actual access density for said determined access density as the stored access density in said means for storing; means for determining when space is required on said second partitioned device means; and means responsive to the stored access density for said given data set for moving said given data set to a partitioned device having an access density more nearly equal to said stored access density.