Loop initialization procedure exception handling for fibre channel transmissions
AssigneeUnisys Corporation
InventorsRalph Ernest Marsh, III, Kathryn Ann McDonald, Willis Lloyd Jacobs
Life of this patent
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Abstract
A fiber optic channel loop provides a transmission path between a computer platform and a multiple number of peripheral devices. When any change occurs in the number of connected peripheral devices or their operation status, then Fiber Channel loop is interrupted so to disable ongoing Input/Output operations to a targeted peripheral device. When this interruption is sensed, the Master Control Program of the platform will institute corrective measures to re-originate any interrupted I/O operations.
Claims21
A method for handling exceptions to any I/O operation between a computer platform operating under a Master Control Program, and selected target peripheral unit, comprising the steps of:
- (a) identifying a target peripheral unit to be sent a data package of X selected bytes;
- (b) organizing by said Master Control Program, an I/O Command Packet with a selected Fibre Channel address and a buffer of data to be transmitted;
- (c) transmitting said buffer of data to a channel manager unit (CMU);
- (d) sending, by said CMU, of said data buffer to a selected Fibre Channel host bus adaptor (HBA) for conveyance to said Fibre Channel target peripheral device;
- (e) sensing by said Fibre Channel HBA, when an interruption to data transmission has occurred because of a Loop Initialization Procedure which operates to send a non-completed I/O signal to said Master Control Program.
A system for handling the notification of interrupted I/O operations between a computer platform and a selected target unit among multiple peripheral units connected to a Fibre Channel Loop comprising:
- (a) Master Control Program means to initiate an I/O data transfer command between a computer platform and a group of target peripheral units connected to a Fibre Optic Channel Loop;
- (b) fibre optic cable means forming an arbitrated transmission loop to said group of multiple peripheral units;
- (c) means to sense an exception condition signal in the I/O command during data transfer operations;
- (d) means for initiating a new Loop Initialization Procedure (LIP) to re-organize the identity numbers of said group of peripheral units when a change has occurred in the number of peripheral units connected to said Fibre Channel Loop for completing incomplete I/O data transfers when possible;
- (e) means for re-trying the transfer of data on those previous incomplete I/O data transfer commands.
A system of handling the notification of interrupted I/O operations between a computer platform means and a target peripheral unit utilizing a Fibre Channel optical cable comprising:
- (a) computer platform means for setting-up an I/O command for communication to multiple peripheral units;
- (b) Fibre Channel Host Bus Adaptor means for transferring a buffer of data from said platform to said target peripheral unit;
- including
- (b1) means for sensing any change in the Fibre Channel cable connections to said multiple peripheral units and for notifying said computer platform;
- (c) means for re-identifying the new channel cable connection arrangements of said multiple peripheral units via signals from said Fibre Channel Host Bus Adaptor;
- (d) means for re-transmitting any incomplete I/O commands to completion or sensing those interrupted I/O commands which are not recoverable.
In a computer platform wherein a Master Control Program organizes an I/O Control Block to utilize an I/O Module for designating a command packet to a Channel Manager Unit to convey data from memory to a Fibre Channel Host Bus Adaptor, a method for detecting a Loop Initialization Procedure for handling data transfers to and from selected peripheral units comprising the steps of:
- (a) sensing the identity of each peripheral device connected to a Fibre Optic loop from a hub connected to said Fiber Channel Host Bus Adaptor;
- (b) initiating a data transfer operation from said Memory to a selected peripheral unit by said Master Control Program.
A platform utilizing a Master Control Program which manages data transmissions to and from selected peripheral units comprising:
- (a) Master Control Program means for enabling data transmission to and receiving data from selected peripheral units;
- (b) I/O Control block means for selecting destination addresses of peripherals and pointers to data in memory to selected peripherals;
- (c) an I/O Module means for utilizing said addresses and memory data into a command packet for conveyance to a Channel Manager Unit;
- (d) a Fibre Channel Host Bus Adaptor means for conveying said memory data to a selected peripheral and for receiving signals as to non-completion of the data transfer;
- (e) means using said Channel Manager and I/O Module to signal non-complete to said Master Control Program.
A method for handling exceptions to I/O operations between a computer platform operating under a Master Control Program (MCP) and selected target peripheral units comprising the steps of:
- (a) initiating a selected data transfer operation using an I/O Control Block by said MCP via an I/O Module, a Command Packet, a Channel Manager Unit (CMU) and Fibre Channel Host Bus Adaptor;
- (b) transmitting by said Fibre Channel Host Bus Adaptor, data transfer operation via a Fibre Channel Loop to selected target peripheral units;
- (c) sensing when a peripheral device has been removed from, or added to said Fibre Channel Loop and sending a Loop Initialization Procedure exception signal to said MCP;
- (d) determining by said MCP, that said data transfer operation Loop Initialization Procedure occurred in the middle of an I/O transfer operation;
- (e) terminating, by said MCP, of said I/O transfer operations.
Dependencies are inferred from the claim text.