Abstract: This invention is a system and method for preparing workload data that may be accessed in a data storage environment and then replayed for testing or other reasons. The invention has the capability to prepare a trace of I/Os to a data storage system for an extended period of time for replaying these I/Os back to that or another system. Variables may also be manipulated through a preparation process and is particularly useful for customizing benchmarking tests, or consolidation, or trouble-shooting, or capacity planning.

Abstract: A method for measuring mass storage system performance in which the mass storage system has a plurality of disk drive storage elements controlled by a disk drive controller, the controller typically having a cache memory, and the controller receiving commands and data from and returning at least data to a plurality of host computers, provides the flexibility of issuing commands to the controller in a variety of different configurations from a plurality of hosts in a time synchronized and organized fashion. Some significant data reduction techniques control and organize the data for later analysis according to the invention. Effective presentation of collected data can be effected using a novel trends analysis presentation approach.

Abstract: A method for measuring mass storage system performance in which the mass storage system has a plurality of disk drive storage elements controlled by a disk drive controller, the controller typically having a cache memory, and the controller receiving commands and data from and returning at least data to a plurality of host computers, provides the flexibility of issuing commands to the controller in a variety of different configurations from a plurality of hosts in a time synchronized and organized fashion. Some significant post processing techniques for validation and correction of the data are enabled according to the invention.

Abstract: This invention is a system and method for preparing workload data that may be accessed in a data storage environment and then replayed for testing or other reasons. The invention has the capability to prepare a trace of I/Os to a data storage system for an extended period of time for replaying these I/Os back to that or another system. Variables may also be manipulated through a preparation process and is particularly useful for customizing benchmarking tests, or consolidation, or trouble-shooting, or capacity planning.

Abstract: This invention is a system and method for replaying workload data that may be accessed in a data storage environment and then replayed for testing or other reasons. The invention has the capability to extract a trace of all I/Os to a data storage system for an extended period of time and then replay these I/Os back to that or another system. Variables may also be manipulated though the play back system to increase testing flexibility at a lower cost than actually introducing new physical variables.

Abstract: This invention is a system and method for preparing workload data that may be accessed in a data storage environment and then replayed for testing or other reasons. The invention has the capability to prepare a trace of I/Os to a data storage system for an extended period of time for replaying these I/Os back to that or another system. Variables may also be manipulated through a preparation process and is particularly useful for customizing benchmarking tests, or consolidation, or trouble-shooting, or capacity planning.

Abstract: A method for measuring mass storage system performance in which the mass storage system has a plurality of disk drive storage elements controlled by a disk drive controller, the controller typically having a cache memory, and the controller receiving commands and data from and returning at least data to a plurality of host computers, provides the flexibility of issuing commands to the controller in a variety of different configurations from a plurality of hosts in a time synchronized and organized fashion. The method features the steps of synchronizing, to a clock time of one of the host computers, designated the master host computer, the clock times of each other of the host computers, designated the client host computers.

Abstract: A method and apparatus for simulating the input/output operations of a memory unit, such as a disk drive array, provide for determining over a predetermined time period, a profile which includes the number of read and write operations for the memory unit and the number of blocks of data read or written during each such operation. The resulting data of the profile is sorted in accordance with the cumulative likelihood of occurrence of the operations, and the read and write operations are then recreated, in a random statistical fashion, in accordance with the sorted resulting data to simulate the frequency of occurrence of the read and write operations at a remote site for the original memory device. The validity of the simulation can be ascertained by repeating the read/write operation collection process during the simulation process and comparing the resulting data with the original data. The simulation can thus take place without adversely affecting operation at the customer's site.

Abstract: A lockset for a door has a strike on the door frame and a latch bolt on the door panel. The latch bolt is reciprocable and is projected by a spring and preferably has a deadlatch operation. The latch bolt is retractable by rotation of an inner knob or of an outer knob. The outer knob is locked by a key lock controlling an axially movable plate engaged with the outer knob and interengageable with an outer escutcheon adjacent the outer knob. The key lock can move the plate out of engagement with the outer escutcheon and into engagement with the inner knob. A turn button in the inner knob can also move the axially movable plate.