# US 8,751,873 B2 · Proactively removing channel paths in error from a variable scope of I/O devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,751,873 B2 - Document ID: US8751873B2 - Status: Granted - Kind: B2 - Application number: 13/663,630 - Filed: 2012-10-30 - Published: 2013-03-28 - Granted: 2014-06-10 - Earliest claimed: 2011-09-28 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Scott B. Compton; Craig D. Norberg; Dale F. Riedy; Harry M. Yudenfriend - Web page: https://patentgrep.com/patent/US8751873B2 ## CPC - G06F 13/4022: {using switching circuits, e.g. switching matrix, connection or expansion network (G06F13/4009 takes precedence)} - G06F 11/0745: {in an input/output transactions management context (input/output processing in general G06F13/00)} - G06F 11/076: {by exceeding a count or rate limit, e.g. word- or bit count limit} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A method includes detecting a channel path error event on an identified channel path; recording channel path error data associated with the detected channel path error event; identifying an scope of the channel path error associated with the identified channel path; determining if the identified channel path is a defective channel path based on the scope of the channel path error; and removing the defective channel path from one or more devices. ## Claims ### Claim 1 A method, comprising: detecting, with a processing device, a channel path error event on an identified channel path, wherein the identified channel path comprises a communication path between a processor and an input/output device; recording, by the processing device, channel path error data associated with the detected channel path error event comprising a two dimensional array having one or more rows that correspond to channel paths and one or more columns that correspond to time periods, wherein each element of the two dimensional array includes a counter configured to store a number of errors that occurred on the identified channel path associated with the element of the two dimensional array during the time period associated with the element of the two dimensional array; determining if an accelerated removal threshold has been met by determining if the counter in two or more time periods within a time interval for a channel path exceeds a threshold value; based on determining that the accelerated removal threshold has been met, removing the identified channel path between the processor and input/output device utilizing the identified channel based on determining that the accelerated removal threshold has not been met, determining if an error threshold has been met; based on determining that the error threshold has been met, identifying a scope of a channel path error associated with the identified channel path; and creating a list of devices affected by the channel path error, determining if the identified channel path is a defective channel path based on the scope of the channel path error. ### Claim 2 (depends on 1) The method of claim 1, wherein determining if an error threshold has been met comprises determining if a sum of the counters in all of the time periods within a time interval for a channel path exceeds a second threshold value. ### Claim 3 (depends on 1) The method of claim 1, wherein identifying the scope of the channel path error further comprises identifying one or more affected devices associated with the channel path error event. ### Claim 4 (depends on 3) The method of claim 3, further comprising removing a defective channel path for all affected devices. ### Claim 5 A method, comprising: detecting, with a processing device, one or more channel path errors on a channel path, wherein the channel path comprises a communication path between a processor and an input/output device; recording, by the processing device, channel path error data associated with the one or more detected channel path errors; identifying a defective channel path based on the channel path error data; and removing the defective channel path between the processor and input/output device; and setting an accelerated removal threshold for a second channel path based on the one or more channel path errors on the defective channel path. ### Claim 6 (depends on 5) The method of claim 5 further comprising: identifying one or more control units associated with the defective channel path; and removing the one or more control units associated with the defective channel path between the processor and input/output device which use the one or more control units. ### Claim 7 (depends on 5) The method of claim 5, wherein the defective channel path comprises a first defective channel path, the method further comprising: detecting one or more channel path errors on a second channel path; identifying a second defective channel path based on the one or more channel path errors on the second channel path; identifying a defective hardware element associated with both the first defective channel path and the second defective channel path; identifying a third defective channel path associated with the defective hardware element; and removing the second and third defective channel paths for all devices which use the defective hardware element. ### Claim 8 (depends on 5) The method of claim 5, wherein each control unit comprises at least one channel and one port. ### Claim 9 (depends on 5) The method of claim 5, wherein identifying a defective channel path based on the one or more channel path errors comprises comparing an average number of the detected channel path errors during a time period with a threshold value. ### Claim 10 (depends on 5) The method of claim 5, wherein identifying a defective channel path based on the one or more channel path errors comprises comparing a total number of the detected channel path errors during a time period with a threshold value.