Apparatus and method for evaluating and predicting computer I/O performance using I/O workload snapshots for model input

Claim 1

A method of using a data processor for providing predicted operation of an I/O system comprised of one or more controllers and one or more storage units cooperating therewith, said I/O system having a plurality of operating delays, said method comprising: programming said processor to provide a simulation model of said I/O system constructed such that said delays are formulated as sets of stochastic processes having settable delay parameters; selectably setting said settable delay parameters by operator control of said simulation model to correspond to said I/O system taking into account said controllers and said storage units and their interconnection; applying to said simulation model signals representing a previously derived I/O workload comprised of a snapshot of I/Os; and producing an output from said simulation module in response to said I/O workload, said output being indicative of said predicted operation; said storage units including a disk device and said simulation model including a statistical submodel which is used by said simulation model for deriving seek delay times for said disk device, said statistical submodel providing a seek time for an I/O operation based on the number of cylinders over which the disk transducer is required to be moved for that I/O operation.

Claim 2

A method of using a data processor for providing predicted operation of an I/O system comprised of one or more controllers and one or more storage units cooperating therewith, said I/O system having a plurality of operating delays, said method comprising: programming said processor to provide a simulation model of said I/O system constructed such that said delays are formulated as sets of stochastic processes having settable delay parameters; selectably setting said settable delay parameters by operator control of said simulation model to correspond to said I/O system taking into account said controllers and said storage units and their interconnection; applying to said simulation model signals representing a previously derived I/O workload comprised of a snapshot of I/Os; and producing an output from said simulation module in response to said I/O workload, said output being indicative of said predicted operation; said storage units including a disk device and said simulation model including a statistical submodel which is used by said simulation model for deriving seek delay times for said disk device, said statistical submodel providing a seek time for an I/O operation based on the number of cylinders over which the disk transducer is required to be moved for that I/O operation.

Claim 3

A method of using a data processor for providing predicted operation of an I/O disk system comprised of one or more controllers and one or more storage units cooperating therewith, said I/O disk system having a plurality of operating delays, said method comprising: programming said processor to provide a simulation model of said I/O system constructed such that said delays are formulated as sets of stochastic processes having settable delay parameters, said stochastic processes being formulated with an index set of arrival position which is integer valuedf and consecutive; applying to said processor signals representing selectable configuration data containing delay parameters associated with various types of controllers and storage units usable in said I/O disk system; selecting under operator control an I/O system configuration from said selectable configuration data; setting said settable delay parameters by operator control of said simulation model to correspond to said selected I/O system configuration; providing selectable I/O workload snapshot data comprised of I/O workload snapshots obtained by measuring actual I/O workloads experienced by an I/O system; selecting under operator control an I/O workload snapshot from said selectable I/O workload snapshot data; driving said simulation model with the selected I/O workload snapshot; and producing an output from said simulation model in response to said selected I/O workload snapshot, said output being indicative of said predicted operation; said storage units including cache storage and said simulation module accounting for said cache storage by using an algorithm representative of cache storage operation.

Claim 4

A method of using a data processor for providing predicted operation of an I/O disk system comprised of one or more controllers and one or more storage units cooperating therewith, said I/O disk system having a plurality of operating delays, said method comprising: programming said processor to provide a simulation model of said I/O system constructed such that said delays are formulated as sets of stochastic processes having settable delay parameters, said stochastic processes being formulated with an index set of arrival position which is integer valuedf and consecutive; applying to said processor signals representing selectable configuration data containing delay parameters associated with various types of controllers and storage units usable in said I/O disk system; selecting under operator control an I/O system configuration from said selectable configuration data; setting said settable delay parameters by operator control of said simulation model to correspond to said selected I/O system configuration; providing selectable I/O workload snapshot data comprised of I/O workload snapshots obtained by measuring actual I/O workloads experienced by an I/O system; selecting under operator control an I/O workload snapshot from said selectable I/O workload snapshot data; driving said simulation model with the selected I/O workload snapshot; and producing an output from said simulation model in response to said selected I/O workload snapshot, said output being indicative of said predicted operation; said storage units including cache storage and said simulation module accounting for said cache storage by using an algorithm representative of cache storage operation.

Claim 12

A method of using a data processor for providing predicted operation of an I/O disk system comprised of one or more controllers and one or more storage units cooperating therewith, said I/O disk system having a plurality of operating delays, said method comprising: programming said processor to provide a simulation model of said I/O system constructed such that said delays are formulated as sets of stochastic processes having settable delay parameters; applying to said processor signals representing selectable configuration data containing delay parameters associated with various types of controllers and storage units usable in said I/O disk system; selecting under operator control an I/O system configuration from said selectable configuration data; setting said settable delay parameters by operator control of said simulation model to correspond to said selected I/O system configuration; providing selectable I/O workload snapshot data comprised of I/O workload snapshots obtained by measuring actual I/O workloads experienced by an I/O system; selecting under operator control an I/O workload snapshot from said selectable I/O workload snapshot data; driving said simulation model with the selected I/O workload snapshot; and producing an output from said simulation model in response to said selected I/O workload snapshot, said output being indicative of said predicted operation; said I/Os of said snapshot being grouped into batches, said simulation model responding to said snapshot on a batch basis as well as on an overall basis based on the weighted average of the results of the individual batches.

Claim 13

A method of using a data processor for providing predicted operation of an I/O disk system comprised of one or more controllers and one or more storage units cooperating therewith, said I/O disk system having a plurality of operating delays, said method comprising: programming said processor to provide a simulation model of said I/O system constructed such that said delays are formulated as sets of stochastic processes having settable delay parameters; applying to said processor signals representing selectable configuration data containing delay parameters associated with various types of controllers and storage units usable in said I/O disk system; selecting under operator control an I/O system configuration from said selectable configuration data; setting said settable delay parameters by operator control of said simulation model to correspond to said selected I/O system configuration; providing selectable I/O workload snapshot data comprised of I/O workload snapshots obtained by measuring actual I/O workloads experienced by an I/O system; selecting under operator control an I/O workload snapshot from said selectable I/O workload snapshot data; driving said simulation model with the selected I/O workload snapshot; and producing an output from said simulation model in response to said selected I/O workload snapshot, said output being indicative of said predicted operation; said I/Os of said snapshot being grouped into batches, said simulation model responding to said snapshot on a batch basis as well as on an overall basis based on the weighted average of the results of the individual batches.