IBM. Link Fault Isolation. Enterprise Systems SY

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1 Enterprise Systems IBM Link Fault Isolation SY

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3 Enterprise Systems IBM Link Fault Isolation SY

4 Note Before using this information and the products it supports, be sure to read the general information under Appendix H, Notices on page H-1. Eleventh Edition (November 2000) This edition obsoletes and replaces all previous editions. This edition applies to the IBM S/390 Enterprise Servers There may be a newer version of this document in PDF format available on Resource Link. Go to and click on Library on the navigation bar. A newer version is indicated by a lower case alphabetic letter following the form number suffix (for example: 00a, 00b, 01a, 01b). Copyright International Business Machines Corporation 1994, All rights reserved. Note to U.S. Government Users Documentation related to restricted rights Use, duplication or disclosure is subject to restrictions set forth in GSA ADP Schedule Contract with IBM Corp.

5 Contents Safety Notices ix World Trade Safety Information ix Product Recycling and Disposal ix Laser Safety Information ix Laser Compliance ix About This Publication xi What Is Included in This Publication xi Related Publications xi How to Send your Comments xii Chapter 1. Link Fault Isolation Start Here MAP 0100: Analyzing the Link-Incident Report MAP 0110: Determining the Link Configuration MAP 0120: Isolating the Link Incident Fault MAP 0130: Using Service Action Codes MAP 0200: Determining Device Installation Problems Chapter 2. Coupling Link Fault Isolation Coupling Facility Link Service Strategy MAP 0300: Coupling Facility Link Fault Isolation Chapter 3. FICON Link Fault Isolation FICON Link Service Strategy MAP 0400: FICON Link Fault Isolation Appendix A. Automated Link Fault Isolation A-1 Appendix B. Link Incident Problem Determination Summary B-1 Link-Incident Codes B-3 Node Identifier B-4 Link Incidents B-4 Appendix C. Link Configuration Summary C-1 Configuration with No Dedicated Connection in an ESCON Director C-1 Configuration with a Dedicated Connection in One ESCON Director C-3 Configuration with Dedicated Connections in Two ESCON Directors C-6 Configuration with Common ESCON Units or Common Links C-10 Appendix D. Using EREP for Link Maintenance Information Analysis D-1 Event History Report Format D-1 Event History Report Example D-3 Detail Edit Report Format and Description D-5 Link Maintenance Information Record Contents D-7 Appendix E. Using ACCESLIR for Link-Incident Reports E-1 Link-Incident Report Format and Description E-1 Link-Incident Report Examples E-4 Coupling Facility Link Format E-6 Copyright IBM Corp. 1994, 2000 iii

6 Appendix F. Service Action Code Summary F-1 Service Action Codes F-1 Appendix G. FICON Link Information and Analysis G-1 Verifying FICON CHPID link status G-1 Identifying FICON nodes G-1 Link Address Key G-1 Appendix H. Notices H-1 Authorized Use of IBM On-line Books H-1 Trademarks H-2 Glossary of Terms and Abbreviations X-1 Index X-5 iv Link Fault Isolation

7 Figures 1-1. No Dedicated Connection in an ESCON Director or a Coupling Facility Link A Dedicated Connection in One ESCON Director Dedicated Connections in Two ESCON Directors Common ESCON Units or Common Links Coupling Facility Link Connection FICON Link Connection B-1. Bit Error Example B-3 C-1. Node Attachment: No Dedicated Connection in an ESCON Director C-1 C-2. Link Incident Example 1: No Dedicated Connection in an ESCON Director C-1 C-3. Link Incident Example 2: No Dedicated Connection in an ESCON Director C-2 C-4. DETAIL EDIT Reports: No Dedicated Connection C-3 C-5. Event Report: No Dedicated Connection C-3 C-6. Node Attachment: Dedicated Connection in One ESCON Director C-4 C-7. Link Incident Example: Dedicated Connection in One ESCON Director C-4 C-8. DETAIL EDIT Reports: One Dedicated Connection C-5 C-9. Event Report: One Dedicated Connection C-5 C-10. Node Attachment: Dedicated Connections in Two ESCON Directors C-6 C-11. Link Incident Example: Dedicated Connections in Two ESCON Directors C-6 C-12. DETAIL EDIT Reports: Two Dedicated Connections C-8 C-13. Event Report: Two Dedicated Connections C-9 C-14. Node Attachment: Common ESCON Units or Common Links C-10 C-15. Link Incident Example: Common ESCON Units or Common Links C-11 C-16. DETAIL EDIT Reports: Common Units or Links C-12 C-17. Event Report: Common Units or Links C-13 D-1. Link Maintenance Information: Event History Report Summary D-1 D-2. Link Maintenance Information: Event History Report Example D-3 D-3. Link Maintenance Information: Detail Edit Report D-5 E-1. Link-Incident Report Format from ACCESSLIR SLC E-1 E-2. Example of Six Link-Incident Reports from ACCESSLIR E-4 E-3. Coupling Facility Link-Incident Report Format from ACCESSLIR SLC E-6 Copyright IBM Corp. 1994, 2000 v

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9 Tables 1-1. Starting Points for Link Fault Isolation Link Configurations No Dedicated Connection in an ESCON Director or a Coupling Facility Link Link-Incident Report: Dedicated Connection in One ESCON Director Link-Incident Report: Dedicated Connections in Two ESCON Directors Service Action Codes Service Action Codes FICON supported configurations D-1. Link Maintenance Information (A2) Record Format D-7 G-1. FICON CHPID and Switch Port Link Error Logging Chart G-2 Copyright IBM Corp. 1994, 2000 vii

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11 Safety Notices World Trade Safety Information Several countries require the safety information contained in product publications to be presented in their national languages. If this requirement applies to your country, a safety information booklet is included in the publications package shipped with the product. The booklet contains the safety information in your national language with references to the US English source publications. Before using a US English publication to install, operate, or service this IBM* product, you must first become familiar with the related safety information in the booklet. You should also refer to the booklet any time you do not clearly understand any safety information in the US English publications. Product Recycling and Disposal Some units contains materials, such as circuit boards and connectors with lead that require special handling and disposal at end of life. Before this unit is disposed, these materials must be removed and recycled or discarded according to applicable regulations. Some products may contain a sealed lead acid battery(s) or a nickel-cadmium battery(s). The battery(s) must be recycled or disposed of properly. Recycling facilities may not be available in your area. In the United States, IBM has established a collection process for reuse, recycling, or proper disposal of used sealed lead acid, nickel cadmium, and nickel metal hydride batteries and battery packs from IBM equipment. For information on proper disposal of the batteries in this product, please contact IBM at For information on disposal of sealed lead acid or nickel cadmium batteries outside the United States, contact your local waste disposal or recycling facility. Some systems contain R-507 refrigerant under high pressure. This refrigerant must not be released or vented to the atmosphere. To avoid risk of personal injury or damage to the system, adding refrigerant or any repair of the refrigerant system must be done by an experienced technician. In some countries, technicians must be certified to specific government requirements. Laser Safety Information Some systems may use PCI, ESCON, or ICS-3 adapters which are fiber optic based and utilize lasers. Laser Compliance All lasers are certified in the U.S. to conform to the requirements of DHHS 21 CFR Subchapter J for class 1 laser products. Outside the U.S., they are certified to be in compliance with the IEC 825 (first edition 1984) as a class 1 laser product. Consult the label on each part for laser certification numbers and approval information. CAUTION: All IBM laser modules are designed so that there is never any human access to laser radiation above a class 1 level during normal operation, user maintenance, or prescribed service conditions. Data processing environments can contain equipment transmitting on system links with laser modules that operate at greater than class 1 power levels. For this reason, never look into the end of an optical fiber cable or open receptacle. Only trained service personnel should perform the inspection or repair of optical fiber cable assemblies and receptacles. Copyright IBM Corp. 1994, 2000 ix

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13 About This Publication This publication is a guide for service personnel who perform hardware problem determination in the Enterprise Systems fiber optic link environment. It provides detailed information and procedures to isolate link failures and to determine the most probable failing element. It also provides a brief overview of this environment and summarizes the general link fault isolation strategy. What Is Included in This Publication This publication contains: Chapter 1. Link Fault Isolation Chapter 2. Coupling Link Fault Isolation Chapter 3. FICON Link Fault Isolation Appendix A. Automated Link Fault Isolation Appendix B. Link Incident Problem Determination Summary Appendix C. Link Configuration Summary Appendix D. Using EREP for Link Maintenance Information Analysis Appendix E. Using ACCESLIR for Link-Incident Reports Appendix F. Service Action Code Summary Appendix G. FICON Link Information and Analysis Related Publications An IBM publication that could be helpful and should be used along with this publication is: SY Maintenance Information for S/390 Fiber Optic Links (ESCON, FICON, Coupling Links, and Open System Adapters) SY Service Guide, Integrated Server 3006 SY Service Guide, Parallel Enterprise Server - Generation 5/6 SY Service Guide, Parallel Enterprise Server - Generation 3/4, Multiprise 2000, Application StarterPak 3000, Coupling Facility Models C04 and C05 SY Service Guide, 9672 Parallel Enterprise Server, 9674 Coupling Facility SY Service Guide, 9672/4 Parallel Server Models E01-E08, P01-P03, R11-R61, C01 SY Model 5 Maintenance Information The following publications provide architecture information about Enterprise Systems Architecture/390 and the ESCON I/O interface: SA SA SA Enterprise Systems Architecture/390 Principles of Operation Enterprise Systems Architecture/390 ESCON I/O Interface Enterprise Systems Architecture/390 Common I/O-Device Commands Copyright IBM Corp. 1994, 2000 xi

14 How to Send your Comments Your feedback is important in helping to provide the most accurate and high-quality information. If you have any comments about this book: Send your comments by using Resource Link at Select Site Feedback on the Navigation bar on the left, then Library Comments, then New Subject. Be sure to include the name of the book, the form number of the book, the version of the book, if applicable, and the specific location of the text you are commenting on (for example, a page number or table number). Fill out one of the forms at the back of this book and return it by mail, by fax, or by giving it to an IBM representative. xii Link Fault Isolation

15 Chapter 1. Link Fault Isolation Each Enterprise Systems product has its own maintenance package that includes online and hardcopy procedures and instructions. When a product can detect, isolate, and report its own failures, the product-specific maintenance package is used to make the repair. When a link incident occurs between products, use this publication to isolate the link fault. Note: For more overview information, see Appendix B, Link Incident Problem Determination Summary on page B-1 and Appendix C, Link Configuration Summary on page C-1. Start Here Start Link Fault Isolation by selecting your situation from the following table. Fast path starting points are provided. Table Situation: 1-1. Starting Points for Link Fault Isolation Start at: FICON Link Failure Chapter 3, FICON Link Fault Isolation on page 3-1 Coupling Facility Link Failure You have a Service Action Code from the link analysis message. No Service Action Code, but EREP reports are available or can be run. No Service Action Code and EREP reports are not available or cannot be run. Chapter 2, Coupling Link Fault Isolation on page 2-1 Step 001 on page 1-2 Step 028 on page 1-6 Step 029 on page 1-6 Other Fast Path Starting Points You do not know the link configuration. You know the link configuration (see Table 1-2 on page 1-15) and the most probable failing unit from the link message or the EREP reports. You know the link configuration and the incident types. You need instructions to identify the most probable failing unit MAP 0110: Determining the Link Configuration on page 1-10 MAP 0120: Isolating the Link Incident Fault on page 1-20 Step 024 on page 1-15 Service Action Codes Service Action Codes are displayed on a console with the link analysis message (analyzer message). These codes are the result of automated analysis completed by the Hardware Management Console or Service Director. Use the code to quickly identify the problem. See MAP Copyright IBM Corp. 1994,

16 MAP 0100: Analyzing the Link-Incident Report Start here to use the Link Message and Service Action Code. If there is no Service Action Code, see Table 1-1 on page Ask the customer or look for the following: A link analysis message that contains: Node identifiers (machine type and serial number). Some listed nodes might not have an identifier. Link interfaces Service action codes Problem data Problem number, so you can refer back to the message, if necessary The physical location of the node or nodes in the network associated with the node identifiers in the message. Obtain the service action code in the message. Refer also to Appendix F, Service Action Code Summary on page F-1. If the service action code: Is between 30 and 53, go to MAP 0130: Using Service Action Codes on page Is not between 30 and 53, go to one of the following steps in this MAP based on the number of nodes specified by the link message: Nodes Listed Go to: One Step 002 Two Step 003 Three Step 019 on page (From step 001) One node listed. The single node is the failing node. Go to the maintenance procedures for the corresponding node. 003 (From step 001) Two nodes listed. Are both nodes identified? Determine the identity of the unidentified unit from the customer's physical configuration. Go to Step 005 on page 1-3. (Step 005 continues) 1-2 Link Fault Isolation

17 005 (continued) (From step 004) Service action code: 1-Y-ZZ; Y and ZZ are not significant. Does the service action code for node 1 begin with 1? Go to Step 008. Unmatched records relating to a dedicated connection in an ESCON Director were received that were not used for this summary analysis. Inspect the customer configuration to determine the actual link connection layout. Contact your next level of support to determine the most probable failing and attached unit. 008 (From step 006) Service action code: X-Y-11; X and Y are not significant. Does the service action code for node 1 end in 11? 009 Service action codes: X-Y-22 through X-Y-26; X and Y are not significant. Does the service action code for node 1 end with a number between 22 and 26? The most probable failing node is Node 1 in the analyzer message. The attached node is node 2. Go to MAP 0120 step 002 on page Determine and remember the following information for later use. Inspect the customer physical configuration to determine if the channel path has a dedicated connection in an ESCON Director and it does not appear in the message. If a dedicated connection does not exist in the channel path, the most probable failing node is node 1 in the analyzer message. Node 2 is the attached node. If a dedicated connection does exist in the channel path, the most probable failing unit is the dedicated port connected by the cable to node 2. Node 2 is the attached node. Service action code: X-0-ZZ; X and ZZ are not significant. (Step 011 continues) Chapter 1. Link Fault Isolation 1-3

18 MAP 0100 (continued) 011 (continued) Is the middle digit of the service action code for node 1 a 0? Go to MAP 0120 step 094 on page Service action code: X-0-22; X is not significant. Does the service action code for node 1 end in 22? Go to MAP 0120 step 002 on page Go to MAP 0120 step 029 on page The cable between the two nodes is the most probable cause of the failure. The cable could be disconnected or broken. Service action code: X-0-ZZ; X and ZZ are not significant. Is the middle digit of the service action code for node 1 a 0? A multiple interface failure (X-1-ZZ) was detected. More than one cable is failing. Go to MAP 0120 step 089 on page A single cable failure was detected. Reconnect the cable if the cable was disconnected. Ensure that all end-of-call completion tasks, if any, in the product-specific maintenance package have been completed for the repair. If the cable was not disconnected, go to MAP 0120 step 024 on page (From step 001) Three nodes listed. Inspect the customer physical configuration to determine if there are any dedicated ports in the path that do not appear as nodes 1, 2, or 3 in the analyzer message. (Step 019 continues) 1-4 Link Fault Isolation

19 019 (continued) Nodes 1, 2, and 3 in the question are shown in the analyzer message. Does node 3 connect to either node 1 or node 2 with an ESCON Director in between? 020 Nodes 1 and 2 in the question are shown in the analyzer message. Is node 2 connected to the interface of node 1? 021 Nodes 1 and 3 in the question are shown in the analyzer message. Are the last two digits of the service action code 17 for node 1? Node 3 in the analyzer message is the most probable failure. Node 1 is the attached node. Go to MAP 0120 step 002 on page The cable between nodes 1 and 3 is the most probable failure. Reconnect the cable if the cable was disconnected. If the cable was not disconnected, go to MAP 0120 step 024 on page Nodes 1 and 2 in the question are shown in the analyzer message. Are the last two digits of the service action code 17 for node 1? Node 2 in the analyzer message is the most probable failure. Node 1 is the attached node. Go to MAP 0120 step 001 on page The cable between nodes 1 and 2 is the most probable failure. Reconnect the cable if the cable was disconnected. If the cable was not disconnected, go to MAP 0120 step 024 on page (Step 027 continues) Chapter 1. Link Fault Isolation 1-5

20 MAP 0100 (continued) 027 (continued) Contact your next level of support. 028 Start at this step when EREP prints are available or can be run. If not, go to Step 029. All link incidents are reported to an operator console. Run an EREP Link Maintenance Information Event History Report and an EREP Link Maintenance Information Detail Edit Report for each processor complex in the customer's system. See Appendix D, Using EREP for Link Maintenance Information Analysis. Go to Step Start here when there is no Service Action Code from a link analysis message and EREP cannot be run. Link-incident records are recorded in a processor controller (PCE) or a hardware management console. To get link-incident records for a 9021 or 9121 CPC: Enter: ACCESLIR at the processor controller (PCE). This service language command reads all link-incident records recorded on the PCE. Each record is formatted and a link-incident report is generated to the console log (CONLOG). Press View Log to view the message. To get link-incident records for a 9672 or 9674 CPC: 1. On the Hardware Management Console workplace window, Open Console Actions from Views. 2. Open View Console Service History. 3. Look for Optical Network (Link) Problem. 4. Select the problem and select View from the menu bar. 5. Select Problem Analysis panels from the pull-down. 6. On the first Problem Analysis window, Select Display Service Information. The second Problem Analysis window displays the link incident information. See Appendix E, Using ACCESLIR for Link-Incident Reports for analysis information and examples. If you are isolating a coupling facility link failure, go to Step 025 on page If not coupling, go to Step (From MAP 0110 step 006 on page 1-11) (From MAP 0110 step 009 on page 1-12) (From MAP 0110 step 014 on page 1-13) (From MAP 0110 step 021 on page 1-14) (From steps 028 and 029) Analyze either the EREP event history report or the link-incident records gathered by the ACCESLIR SLC. See Event History Report Example on page D-3 for an example of an EREP event history report. (Step 030 continues) 1-6 Link Fault Isolation

21 030 (continued) See Link-Incident Report Examples on page E-4 for an example of a link-incident report. 1. Locate all reports that relate to the same link incident. A group of reports probably relates to the same incident if: The incident node ID (type, model, sequence number, and interface) of one report is the same as the attached node ID of another report. The incident node IDs and/or attached node IDs from the reports have the same type and model, but different interfaces (such as a group of records reported by different interfaces on the same unit; for example, a set of channels on the same processor). Note: Any records reported for an ESCON Director port having a dedicated connection cannot be matched using the node IDs. Each of these reports must be grouped with other reports based on time stamp and knowledge of the customer's I/O configuration. 2. Start by taking any reports matched by node IDs; note the time stamp on these reports. Any ESCON Director reports that have a time stamp close to these reports could be associated with the same incident. Refer to the environmental error record editing and printing program (EREP) detail edit reports in the EREP printout or to the link-incident reports from the CONLOG. 3. Check nodes in the reports against the actual customer configuration. Go to Step 031 on page 1-8. Chapter 1. Link Fault Isolation 1-7

22 MAP 0100 (continued) 031 (From step 030) Determining Where a Link Begins and Ends A link incident includes information about the links and any ESCON Director dedicated connections in a single channel path. However, one channel path can include more than one link. In the figure below, for example, the connection between ESCON Director ports P1 and P2 is dynamic. Link-incident reports would then show this channel path as two different link segments. One segment is from Node A to port P1; the second segment is from the other dynamically-connected port (P2) to Node B. Both of these link segments are the same and would then match the configuration shown in Figure 1-1 on page 1-9 (no dedicated connection). The figure below adds a second ESCON Director between port P2 and Node B. In this example, the connection between the ports in the second Director (P3 and P4) is dedicated. Therefore, this channel path also has two link segments, but their configurations are different. Segment 1 starts at the Node A and ends at port P1; segment 2 starts at port P2, goes through the dedicated connection between ports P3 and P4 and ends at Node B. For this example, the first link segment matches to no dedicated connections in an ESCON Director, but the second matches to a dedicated connection in one ESCON Director. In summary, a link between two nodes in the same channel path cannot begin or end at an ESCON Director port that has a dedicated connection in that channel path. Using the customer's configuration, determine what link (segment) in the channel path is associated with each link-incident report. Each group of reports and the associated link (segment) must be matched to one of the configurations shown in Figure 1-1 to Figure 1-4 on page 1-9. Go to MAP 0110: Determining the Link Configuration on page Link Fault Isolation

23 Figure 1-1. No Dedicated Connection in an ESCON Director or a Coupling Facility Link Figure 1-2. A Dedicated Connection in One ESCON Director Figure 1-3. Dedicated Connections in Two ESCON Directors (A) Node B Node C Node A Node D Node E (B) Node A Node B Figure 1-4. Common ESCON Units or Common Links. An ESCON unit can contain 2 or more nodes reporting related link incidents (for example, an ESCON Director reporting related link incidents from 2 or more ports). Chapter 1. Link Fault Isolation 1-9

24 MAP 0110: Determining the Link Configuration 001 For coupling facility channel links, go to Step 025 on page 1-16 This MAP describes how to determine the failing segment of the channel path by taking a group of link-incident reports associated with a link incident. The channel path segment is matched with one of the four link configurations shown in Figure 1-1 through Figure 1-4 on page 1-9. Each record in the group is then matched with one of the nodes in the link configuration diagram. See Appendix C, Link Configuration Summary for additional information. Check the dedicated connection interface (DCI) link-incident records field in the ACCESLIR or EREP data. N/A in this field means that the record was not reported by an ESCON Director with a dedicated connection. If an interface is specified (for example, 0011), the record was reported. Go to the next step as directed by the following table: Number of records reported by an ESCON Director with a dedicated connection: Total of all unique reports in the group (dedicated and dynamic): Go to: Some Step 002 None One Two More than two Step 003 on page 1-11 Step 004 on page 1-11 Step 009 on page (From step 001) Check to see how many different ESCON Directors have reported records. Do this by checking the node IDs in the reports. Each different type-model-sequence number combination is a different ESCON Director. Go to the next step as directed by the following table: Number of ESCON Directors with dedicated connections: One Number of reports in this group NOT reported by a dedicated port in an ESCON Director: None One Two More than two Go to: Step 010 on page 1-12 Step 011 on page 1-12 Step 012 on page 1-13 Step 009 on page Link Fault Isolation

25 Number of ESCON Directors with dedicated connections: Two More than two Number of reports in this group NOT reported by a dedicated port in an ESCON Director: None One Two More than two Go to: Step 017 on page 1-13 Step 018 on page 1-14 Step 019 on page 1-14 Step 009 on page 1-12 Step 009 on page (From step 001) The segment of the channel path most probably matches the one shown in Figure 1-1 on page 1-9. For use in a table lookup in a later step, match the report to node A. Go to Step 024 on page The link configuration is: no dedicated connection in an ESCON Director or a coupling facility link connection. 004 (From step 001) Check the node IDs in the reports. Does the incident node ID from each report match the attached node ID from the other report? 005 Do both reports have the same attached unit? The records in this group probably are not all associated with the same link incident. Return to MAP 0100: Analyzing the Link-Incident Report at MAP 0100 step 030 on page 1-6 and regroup the link-incident reports. Go to Step 009 on page The segment of the channel path most probably matches the one shown in Figure 1-1 on page 1-9. (Step 008 continues) Chapter 1. Link Fault Isolation 1-11

26 MAP 0110 (continued) 008 (continued) For use in a table lookup in a later step, match one report to node A and the other report to node B. Go to Step 024 on page The link configuration is: no dedicated connection in an ESCON Director or a coupling facility link connection. 009 (From steps 001, 002, 007, 015, and 022) Check the node IDs in the reports, checking for one or two common ESCON units. Common ESCON units are identified by finding node IDs that have the same type, model, and sequence number, but different interfaces. An example of this might be several ports on an ESCON Director. If one or two common ESCON units are identified, the configuration most probably matches the one shown in Figure 1-4 on page 1-9. Go to Step 024 on page The link configuration is: common ESCON units or common links. If no common ESCON units are identified, the reports in this group probably are not all associated with the same link incident. Return to MAP 0100: Analyzing the Link-Incident Report at MAP 0100 step 030 on page 1-6 and regroup the link-incident reports. 010 (From step 002) The segment of the channel path most probably matches the one shown in Figure 1-2 on page 1-9. For use in a table lookup in a later step, match the reports from the ESCON Director dedicated ports to ports P1 and P2 in the figure (it does not matter which report is assigned to P1 and which to P2). Then refer to the customer configuration information (layout diagram, I/O physical cabling map, IOCDS information, and so on) to determine the identity of nodes A and B, even though there are no records reported from these nodes. It might become important later in the repair to be able to identify these nodes. Go to Step 024 on page The link configuration is: a dedicated connection in one ESCON Director. 011 (From step 002) The segment of the channel path most probably matches the one shown in Figure 1-2 on page 1-9. For use in a table lookup in a later step, match the report that did not come from an ESCON Director dedicated port to node A. Then refer to the customer's configuration information (layout diagram, I/O physical cabling map, IOCDS information, and so on) to determine which ESCON Director port is connected to this node. This port is matched with port P1 in the figure. The other ESCON Director port is matched to port P2 in the figure. If there is no report from the other port, it is identified in the DCI field of the report from the port matched to P1. Although there is no report to be matched with node B, the attached node ID from the report matched to node A should identify node B. Go to Step 024 on page The link configuration is: a dedicated connection in one ESCON Director. 012 (Step 012 continues) 1-12 Link Fault Isolation

27 012 (continued) (From step 002) Check the node IDs in the reports that are not from ESCON Director dedicated ports. Does the incident node ID from each report match the attached node ID from the other report? 013 Do both reports have the same attached unit? The reports in this group probably are not all associated with the same link incident. Return to MAP 0100: Analyzing the Link-Incident Report at MAP 0100 step 030 on page 1-6 and regroup the link-incident reports. Go to Step 009 on page The segment of the channel path most probably matches the one shown in Figure 1-2 on page 1-9. For use in a table lookup in a later step, match the two reports that did not come from an ESCON Director dedicated port to nodes A and B (it does not matter which is assigned to A and which to B). Then refer to the customer's configuration information (layout diagram, I/O physical cabling map, IOCDS information, and so on) to determine which ESCON Director port is connected to node A. This port is matched with port P1 in the figure. The other ESCON Director port is matched to port P2 in the figure. If there is no report from the other port, it is identified in the DCI field of the report from the port matched to P1. Go to Step 024 on page The link configuration is: a dedicated connection in one ESCON Director. 017 (From step 002) The segment of the channel path most probably matches the one shown in Figure 1-3 on page 1-9. For use in a table lookup in a later step, match the reports from the ESCON Director dedicated ports to ports P1, P2, P3, and P4 in the figure. First divide the reports into two groups, one for each ESCON Director (the type-model-sequence number is used to make this distinction). You should have either one or two reports in each group. Then refer to the customer's configuration information (layout diagram, I/O physical cabling map, IOCDS information, and so on) to determine the two ESCON Director ports that are connected between the two ESCON Directors. Match these ports to P2 and P3 in the figure; it does not matter which is matched with P3 and which with P4. Then, based on the DCI fields of the reports associated with the first ESCON Director, determine the port that has a dedicated connection with the port matched with P2, and match this port with P1. Similarly, identify the port to be matched to P4 in the figure by examining the DCI fields of the reports associated with the second ESCON Director. Again using the customer's configuration information, identify nodes A and B, even although there are no records reported from these nodes. (It could become important later in the repair to be able to identify these nodes.) (Step 017 continues) Chapter 1. Link Fault Isolation 1-13

28 MAP 0110 (continued) 017 (continued) Go to Step 024 on page The link configuration is: dedicated connections in two ESCON Directors. 018 (From step 002) The segment of the channel path most probably matches the one shown in Figure 1-3 on page 1-9. For use in a table lookup in a later step, match the report that did not come from an ESCON Director dedicated port to node A. Then refer to the customer's configuration information (for example, layout diagram, I/O physical cabling map, and IOCDS information) to determine which ESCON Director port is connected to this node. This port is matched with port P1 in the figure. Determine the port to be matched to P2 from the DCI field of the report from the port matched to P1 (there could possibly be a report from the port matched to P2). Then refer to the customer's configuration information to determine what ESCON Director port on the second ESCON Director is connected to port P2, and match that port to port P3 in the figure. The identity of the port that matches P4 in the figure can be determined from the DCI field of the report from the port matched to P3 (again, there could possibly be a report from the port matched to P4). Although there is no report to be matched with node B, the attached node ID from the report matched to node A should identify node B. Go to Step 024 on page The link configuration is: dedicated connections in two ESCON Directors. 019 (From step 002) Check the node IDs in the reports that are not from ESCON Director dedicated ports. Does the incident node ID from each report match the attached node ID from the other report? 020 Do both reports have the same attached unit? The reports in this group probably are not all associated with the same link incident. Return to MAP 0100: Analyzing the Link-Incident Report at MAP 0100 step 030 on page 1-6 and regroup the link-incident reports. Go to Step 009 on page The segment of the channel path most probably matches the one shown in Figure 1-3 on page 1-9. For use in a table lookup in a later step, match the two reports that did not come from an ESCON Director dedicated port to nodes A and B (it does not matter which is assigned to A and which to B). Then refer to the customer's configuration information to determine what ESCON Director port on the 1-14 Link Fault Isolation

29 2nd ESCON Director is connected to port P2, and match that port to port P3 in the figure. The identity of the port that matches P4 in the figure can be determined from the DCI field of the report from the port matched to P3 (again, there could possibly be a report from the port matched to P4). Go to Step 024. The link configuration is: dedicated connections in two ESCON Directors. 024 (From steps 003, 008, 009, 010, 011, 016, 017, 018, and 023) Note: Tables in the later steps depend on configuration and the number of link-incident reports. Please note the following: Any of the tables can be used with partial information if all of the reports indicated are not present. Disregard any column for which no information is available unless the content of a specific cell in the column says none (there is no link record). Bit error rate exceeded threshold (BER) failures can be reported in more than one link. The BER failure can occur in one link and pass through a dynamic connection to another link. Be sure to first examine the link associated with the earlier report. A report can show a node ID as invalid. For example, a record reported by an ESCON Director dedicated port will not have a valid attached node ID. In these instances, the identity of the attached unit must be determined from the actual customer I/O configuration. If more than one report is received from the same node, with some reports indicating bit-error-rate threshold exceeded and some reports indicating other types of link incidents, the bit-error-rate threshold exceeded reports can be ignored. Also, the following notation is used to show the link-incident type: 1 - Implicit Implicit incident 2 - BER Bit-error-rate threshold exceeded 3 - LOSS Loss of signal or synchronization (link failure) 4 - NOS Not Operational Sequence received 5 - Seq TO Sequence time-out (link failure) 6 - Ill Seq Illegal sequence for link-level facility state (link failure) The link incident is decoded from the byte following the IC= designation in the link-incident report in ACCESLIR or EREP. An example is in Figure D-2 on page D-3. The incident code byte is decoded in step 5, incident code on page D-2. Based on the segment of the channel path for this link incident, refer to the following table to determine the next step. Table 1-2. Link Configurations Link Configuration: No dedicated connection in an ESCON Director or a coupling facility link. (Figure 1-1 on page 1-9). Go to: Step 025 on page 1-16 A dedicated connection in one ESCON Director (Figure 1-2 on page 1-9). Step 026 on page 1-17 Dedicated connections in two ESCON Directors (Figure 1-3 on page 1-9). Step 027 on page 1-18 Common ESCON units or common links (Figure 1-4 on page 1-9). Step 028 on page (Step 025 continues) Chapter 1. Link Fault Isolation 1-15

30 MAP 0110 (continued) 025 (continued) (From step 024) The segment of the channel path for this link incident contains two nodes connected point-to-point, and does not include a dedicated connection in an ESCON Director (Figure 1-1 on page 1-9). Either one or two reports are available. Use the link incident reports and the following table to determine the most probable failing unit. Table 1-3. No Dedicated Connection in an ESCON Director or a Coupling Facility Link Incident Type Node A Incident Type Node B Most Probable Failing Unit 1-Implicit Any type or none Node A Any type or none 1-Implicit Node B 2-BER None Node B None 2-BER Node A 3-LOSS None Node B None 3-LOSS Node A 4-NOS None Node A None 4-NOS Node B 5-Seq TO None Node B None 5-Seq TO Node A 6-Ill Seq None Node B None 6-Ill Seq Node A 3-LOSS 4-NOS Node B 4-NOS 3-LOSS Node A 3-LOSS Cable between nodes A and B 5-Seq TO 4-NOS Node B 4-NOS 5-Seq TO Node A 6-Ill Seq 4-NOS Node B 4-NOS 6-Ill Seq Node A 4-NOS 4-NOS No failure. Cable plugged when not offline. Abbreviations: Implicit incident BER Bit-error-rate threshold exceeded LOSS Loss of signal or synchronization (link failure) NOS Not Operational Sequence received Seq TO Sequence time-out (link failure) Ill Seq Illegal sequence for link-level facility state (link failure) Note: A failing cable includes the distribution panel, jumper cable, and trunk cable. The most probable failing unit has been determined. Go to MAP 0120: Isolating the Link Incident Fault on page (Step 026 continues) 1-16 Link Fault Isolation

31 026 (continued) (From step 024) The segment of the channel path for this link incident contains two nodes (channels, control units, or ESCON Director ports) and includes a dedicated connection in one ESCON Director (see Figure 1-2 on page 1-9). As many as four reports could be available. Table Incident Type Node A 1-Implicit Any type or none Any type or none Any type or none 1-4. Link-Incident Report: Dedicated Connection in One ESCON Director ESCON Director Port P1 Any type or none 1-Implicit Any type or none Any type or none ESCON Director Port P2 Any type or none Any type or none 1-Implicit Any type or none Incident Type Node B Any type or none Any type or none Any type or none 1-Implicit Most Probable Failing Unit Node A ESCON Director port P1 ESCON Director port P2 Node B None 2-BER None None Node A None 2-BER None 2-BER Node A None None 2-BER None Node B 2-BER None 2-BER None Node B 2-BER None None None ESCON Director port P1 None None None 2-BER ESCON Director port P2 4-NOS 3-LOSS 4-NOS 3-LOSS Node A 3-LOSS 4-NOS None 4-NOS ESCON Director port P1 4-NOS None 4-NOS 3-LOSS ESCON Director port P2 3-LOSS 4-NOS 3-LOSS 4-NOS Node B 3-LOSS 3-LOSS 4-NOS 3-LOSS Cable between node A and port P1 3-LOSS 4-NOS 3-LOSS 3-LOSS Cable between port P2 and node B 4-NOS None 4-NOS 5-Seq TO Node A 5-Seq TO 4-NOS None 4-NOS Node B 4-NOS None 4-NOS 6-Ill Seq Node A 6-Ill Seq 4-NOS None 4-NOS Node B 4-NOS 4-NOS None 4-NOS No failure. Cable between node A and port P1 plugged when not offline. 4-NOS None 4-NOS 4-NOS No failure. Cable between node B and port P2 plugged when not offline. Abbreviations: Implicit Implicit incident BER Bit-error-rate threshold exceeded LOSS Loss of signal or synchronization (link failure) NOS Not Operational Sequence received Seq TO Sequence time-out (link failure) Ill Seq Illegal sequence for link-level facility state (link failure) Note: A failing cable includes the distribution panel, jumper cable, and trunk cable. Chapter 1. Link Fault Isolation 1-17

32 MAP 0110 (continued) The most probable failing unit has been determined. Go to MAP 0120: Isolating the Link Incident Fault on page (From step 024) The segment of the channel path for this link incident contains two nodes (channels, control units, or ESCON Director ports) and includes dedicated connections in two ESCON Directors (see Figure 1-3 on page 1-9). As many as six reports could could be available. Table Incident Type Node A 1-Implicit Any type or none Any type or none Any type or none Any type or none Any type or none 1-5 (Page 1 of 2). Link-Incident Report: Dedicated Connections in Two ESCON Directors ESCON Director Port P1 Any type or none 1-Implicit Any type or none Any type or none Any type or none Any type or none ESCON Director Port P2 Any type or none Any type or none 1-Implicit Any type or none Any type or none Any type or none ESCON Director Port P3 Any type or none Any type or none Any type or none 1-Implicit Any type or none Any type or none ESCON Director Port P4 Any type or none Any type or none Any type or none Any type or none 1-Implicit Incident Type Node B Any type or none Any type or none Any type or none Any type or none Any type or none Most Probable Failing Unit Node A Any type or none 1-Implicit Node B None 2-BER None 2-BER None None Node A None 2-BER None 2-BER None 2-BER Node A ESCON Director port P1 ESCON Director port P2 ESCON Director port P3 ESCON Director port P4 2-BER None None None None None ESCON Director port P1 None None None 2-BER None None ESCON Director port P2 None None None 2-BER None 2-BER ESCON Director port P2 None None 2-BER None None None ESCON Director port P3 2-BER None 2-BER None None None ESCON Director port P3 None None None None None 2-BER ESCON Director port P4 None None 2-BER None 2-BER None Node B 2-BER None 2-BER None 2-BER None Node B 4-NOS 3-LOSS 4-NOS 3-LOSS 4-NOS 3-LOSS Node A 3-LOSS 4-NOS None 4-NOS None 4-NOS ESCON Director port P1 4-NOS None 4-NOS 3-LOSS 4-NOS 3-LOSS ESCON Director port P2 3-LOSS 4-NOS 3-LOSS 4-NOS None 4-NOS ESCON Director port P3 4-NOS None 4-NOS None 4-NOS 3-LOSS ESCON Director port P4 3-LOSS 4-NOS 3-LOSS 4-NOS 3-LOSS 4-NOS Node B 3-LOSS 3-LOSS 4-NOS 3-LOSS 4-NOS 3-LOSS 3-LOSS 4-NOS 3-LOSS 3-LOSS 4-NOS 3-LOSS Cable between node A and port P1 Cable between ports P2 and P Link Fault Isolation

33 Table Incident Type Node A 1-5 (Page 2 of 2). Link-Incident Report: Dedicated Connections in Two ESCON Directors ESCON Director Port P1 ESCON Director Port P2 ESCON Director Port P3 ESCON Director Port P4 Incident Type Node B 3-LOSS 4-NOS 3-LOSS 4-NOS 3-LOSS 3-LOSS 4-NOS None 4-NOS None 4-NOS 5-Seq TO Node A 5-Seq TO 4-NOS None 4-NOS None 4-NOS Node B 4-NOS None 4-NOS None 4-NOS 6-Ill Seq Node A 6-Ill Seq 4-NOS None 4-NOS None 4-NOS Node B Abbreviations: Implicit Implicit incident BER Bit-error-rate threshold exceeded LOSS Loss of signal or synchronization (link failure) NOS Not Operational Sequence received Seq TO Sequence time-out (link failure) Ill Seq Illegal sequence for link-level facility state (link failure) Note: A failing cable includes the distribution panel, jumper cable, and trunk cable. Most Probable Failing Unit Cable between port P4 and node B The most probable failing unit has been determined. Go to MAP 0120: Isolating the Link Incident Fault on page (From step 024) The segment of the channel path for this link incident contains multiple links attached to one or more common ESCON units (see Figure 1-4 on page 1-9). If the configuration matches part A of the figure, and there is either no report from ESCON unit A or there is a report from ESCON unit A that indicates an implicit incident (1-Implicit), most probably a node failure exists and a node in ESCON unit A is the most probable failing node. If the configuration matches part B of the figure, and there is either no report or there is a report that indicates an implicit incident (1-Implicit) from one of the ESCON units, most probably a node failure exists in that unit, and that unit is the most probable failing unit. If the configuration matches part B of the figure and there are reports from nodes on both ends of the collection of links, and the type of incident detected by the majority of nodes on both ends is a link failure because of loss of signal or synchronization (3-LOSS), then most probably a trunk failure exists and the most probable failing unit is a common trunk cable or collection of links running between the two ESCON units. The most probable failing unit has been determined. Go to MAP 0120: Isolating the Link Incident Fault on page Chapter 1. Link Fault Isolation 1-19

34 MAP 0120: Isolating the Link Incident Fault 001 (From MAP 0100 step 025 on page 1-5) Note: These MAP steps refer to a most probable failing unit and a node connected to the most probable failing unit. The most probable failing unit is the node (identified by type, model, interface, and sequence number) that was identified as the most likely cause of the link incident by using MAP 0100: Analyzing the Link-Incident Report. The node connected to the most probable failing unit is the particular unit and interface that is connected by a link to the most probable failing unit. Use this MAP for all reported link incidents. You should already know the link configuration, have the information reported by the nodes involved in the link incident, and know the most probable failing unit. If not, go to Start Here on page 1-1. Before referring to the following table, be aware that a bit-error-rate threshold exceeded incident can be caused by unlatched or dirty connectors. Note: Service action code 02, 14, or 22 indicates a BER threshold exceeded. Check that the connector is properly latched by pressing both latches simultaneously on the grooved angled shoulders with your thumb and first finger. 1. If the connector was unlatched, check if the link is operational now. 2. If the link is still not operational, clean the connector ferrules using the materials and procedures described in Fiber Optic Cleaning Procedures, refer to Related Publications on page xi. Again check if the link is operational. 3. If the link is still not operational, use the following table to determine the next step Link Fault Isolation