Method of sensing target status in a local area network
First Claim
1. A method of providing any of a plurality of host processors ATTENTION DATA and PM DATA on any of a plurality of SCSI targets through a controller, said controller including a host adapter, microprocessor, only one SCSI initiator, and memory, with said memory comprising separate addresses for ATTENTION DATA from each of said plurality of SCSI targets for each of said plurality of host processors on a one to one basis so that ATTENTION DATA from one of said plurality of SCSI targets for one of said host processors can be cleared without clearing any other ATTENTION DATA, with said method comprising the steps of:
- receiving at said controller a command from one of said plurality of host processors for one of said plurality of SCSI targets;
determining if said controller contains ATTENTION DATA from said one of said plurality of SCSI targets;
determining if said command is a request for ATTENTION DATA when said controller contains ATTENTION DATA from said one of said plurality of SCSI targets;
returning ATTENTION DATA from said controller to said one of said plurality of host processors for said one of said plurality of SCSI targets and clearing at said controller only the ATTENTION DATA for said one of said plurality of host processors from said one of said plurality of SCSI targets when said command is a request for ATTENTION DATA; and
returning PM DATA for said one of said plurality of SCSI targets when said controller does not contain ATTENTION DATA and command is a PM REQUEST.
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Accused Products
Abstract
An SCSI controller adapted as a network file server provides a virtual coction between a plurality of host processors and a single SCSI initiator. The controller contains a removable host adapter for connection to any type of network interface. When a host processor issues a command packet and requests status information of a target device, that status information is passed to the requesting processor and subsequently stored in the controller and made available to all other host processors on the network. A fault tolerant performance monitoring algorithm, executing within the controller, is scheduled to non-intrusively and periodically check the status of each SCSI target device and to store that status information for all host processors. The advantage to such a controller is the expanded number of host processor connections to a single SCSI initiator whereby each host processor can independently and logically connect through the controller and SCSI initiator to a target without clearing target status information for other host processors.
46 Citations
5 Claims
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1. A method of providing any of a plurality of host processors ATTENTION DATA and PM DATA on any of a plurality of SCSI targets through a controller, said controller including a host adapter, microprocessor, only one SCSI initiator, and memory, with said memory comprising separate addresses for ATTENTION DATA from each of said plurality of SCSI targets for each of said plurality of host processors on a one to one basis so that ATTENTION DATA from one of said plurality of SCSI targets for one of said host processors can be cleared without clearing any other ATTENTION DATA, with said method comprising the steps of:
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receiving at said controller a command from one of said plurality of host processors for one of said plurality of SCSI targets; determining if said controller contains ATTENTION DATA from said one of said plurality of SCSI targets; determining if said command is a request for ATTENTION DATA when said controller contains ATTENTION DATA from said one of said plurality of SCSI targets; returning ATTENTION DATA from said controller to said one of said plurality of host processors for said one of said plurality of SCSI targets and clearing at said controller only the ATTENTION DATA for said one of said plurality of host processors from said one of said plurality of SCSI targets when said command is a request for ATTENTION DATA; and returning PM DATA for said one of said plurality of SCSI targets when said controller does not contain ATTENTION DATA and command is a PM REQUEST. - View Dependent Claims (2, 3, 4, 5)
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Specification