Composite drive controller including composite disk driver for supporting composite drive accesses and a pass-through driver for supporting accesses to stand-alone SCSI peripherals
First Claim
1. A drive array controller connectable to a host computer, wherein the host computer includes a first device driver configured to generate a peripheral access request having a SCSI command descriptor block embedded therein and a second device driver configured to generate a composite drive access request, said drive array controller comprising:
- a first request interface coupled to receive said peripheral access request from said first device driver;
a pass-through driver coupled to said first request interface, wherein said pass-through driver is configured to extract said SCSI command descriptor block from said peripheral access request;
a second request interface coupled to receive said composite drive access request from said second device driver and configured to generate a composite command block containing information for accessing a composite drive;
a composite disk driver coupled to said second request interface and configured to translate a composite drive location indicated within said composite command block to a physical drive location, wherein said composite disk driver is further configured to provide the physical drive location within a physical drive control block;
a SCSI device driver coupled to receive said SCSI command descriptor block from said pass-through driver and configured to provide said SCSI command descriptor block to a SCSI bus having a plurality of SCSI peripherals coupled thereto during a first mode, and wherein said SCSI device driver is further coupled to receive said physical drive control block and is configured to derive a separate SCSI command descriptor block from said physical drive control block and is configured to provide said separate SCSI command descriptor block to said SCSI bus during a second mode; and
a virtual disk driver configured to generate a command block containing information for storing redundant data within said composite drive and coupled to provide said command block to said SCSI device driver.
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Accused Products
Abstract
A drive array controller is provided that serves as an interface between both stand-alone SCSI devices as well as SCSI devices that form a composite drive. Since an AHA emulation interface is incorporated on the drive array controller, the drive array controller is compatible with conventional AHA device drivers that drive stand-alone peripheral devices such as SCSI CD-ROM units and SCSI tape drives. The drive array controller includes a SCSI pass-through driver that extracts a SCSI command descriptor block from a command control block created by the AHA device driver. The drive array controller further provides a separate peripheral access channel to support high speed composite drive operations through a composite device driver. Since the AHA emulation interface and a composite drive interface are provided on a common peripheral board, only one EISA expansion slot is occupied.
126 Citations
14 Claims
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1. A drive array controller connectable to a host computer, wherein the host computer includes a first device driver configured to generate a peripheral access request having a SCSI command descriptor block embedded therein and a second device driver configured to generate a composite drive access request, said drive array controller comprising:
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a first request interface coupled to receive said peripheral access request from said first device driver; a pass-through driver coupled to said first request interface, wherein said pass-through driver is configured to extract said SCSI command descriptor block from said peripheral access request; a second request interface coupled to receive said composite drive access request from said second device driver and configured to generate a composite command block containing information for accessing a composite drive; a composite disk driver coupled to said second request interface and configured to translate a composite drive location indicated within said composite command block to a physical drive location, wherein said composite disk driver is further configured to provide the physical drive location within a physical drive control block; a SCSI device driver coupled to receive said SCSI command descriptor block from said pass-through driver and configured to provide said SCSI command descriptor block to a SCSI bus having a plurality of SCSI peripherals coupled thereto during a first mode, and wherein said SCSI device driver is further coupled to receive said physical drive control block and is configured to derive a separate SCSI command descriptor block from said physical drive control block and is configured to provide said separate SCSI command descriptor block to said SCSI bus during a second mode; and a virtual disk driver configured to generate a command block containing information for storing redundant data within said composite drive and coupled to provide said command block to said SCSI device driver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for interfacing a plurality of SCSI devices to a host computer system comprising the steps of:
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receiving a peripheral access request having a SCSI command descriptor block embedded therein at a first request interface through an expansion slot of said host computer system; extracting said SCSI command descriptor block from said peripheral access request; providing said SCSI command descriptor block to a SCSI bus; receiving a composite drive access request at a second request interface through said expansion slot of said host computer system; translating a composite drive location indicated within said composite drive access request to a physical drive location to thereby create a physical drive command request; converting said physical drive command request to a second SCSI command descriptor block; providing said second SCSI command descriptor block to said SCSI bus; and creating a control block corresponding to said composite drive access request, wherein said control block is for storing redundant data.
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Specification