Error Handling and Recovery for Storage Control Units
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
The error-handling procedure shown in Fig. 3 allows the storage control elements (SCEs) 10 and 12 of main storage elements (MSEs) 14 and 16 to recover from error conditions without the multiprocessing system shown in Fig. 1 going through a check stop state. Error checkers for the SCEs 10 and 12 detect two types of failures. An error detected by either the type A checker 18 or the type B checker 20 results in the failing SCE notifying the operational SCE and the other functional elements of the system, i.e., CPUs 22, the I/O channels 24 and the processor controllers 26, that it is going into an error-handling and -recovery procedure and not to send anymore requests. If a type A error is detected, the SCE will enter a phase A mode of operation and process all requests outstanding at the time it sends the notice.