IPI-3 Physical Level Intermittent Failure Recovery/Trend Analysis
Original Publication Date: 1988-Apr-01
Included in the Prior Art Database: 2005-Feb-15
By defining a set of error recovery/logging counters for use in tracking Intelligent Peripheral Interface-3 (IPI-3) physical level intermittent errors, retry capability is provided from the point of initial error detection (the I/O processor) rather than at the command level by the operating system. In addition, a cumulative data analysis algorithm is used to differentiate between errors caused by noise bursts and those caused by intermittently failing Field Replaceable Units (FRU's), an otherwise difficult task. There are a number of physical level errors that can occur on the IPI-3 used to attach an I/O Processor (IOP) to Direct Access Storage Device (DASD) and tape devices. These errors are categorized as follows: ~ Parity errors Parity errors are detected by either the device or IOP hardware.