HP AE370A HP StorageWorks Fabric OS 6.x administrator guide (5697-0015, May 20 - Page 301

14 Troubleshooting This chapter provides information on troubleshooting and the most common procedures to use to diagnose and recover from problems. It also includes specific troubleshooting scenarios as examples. About troubleshooting Troubleshooting should begin at the center of the SAN-the fabric. Because switches are located between the hosts and storage devices and have visibility into both sides of the storage network, starting with them can help narrow the search path. After eliminating the possibility of a fault within the fabric, see if the problem is on the storage side or the host side, and continue a more detailed diagnosis from there. Using this approach can quickly pinpoint and isolate problems. For example, if a host cannot detect a storage device, run a switch command, for example switchShow to determine if the storage device is logically connected to the switch. If not, focus first on the switch directly connecting to storage. Use the diagnostic tools in Table 67 to better understand why it is not visible to the switch. If the storage can be detected by the switch, and the host still cannot detect the storage device, then there is still a problem between the host and switch. Most common problem areas Table 67 lists the most common problem areas that arise within SANs and identifies tools to use to resolve them. Table 67 Common troubleshooting problems and tools Problem area Investigate Tools Fabric • Missing devices • Marginal links (unstable connections) • Incorrect zoning configurations • Incorrect switch configurations • Switch LEDs • Switch commands (for example, switchShow or nsAllShow) for diagnostics • Web or GUI-based monitoring and management software tools Storage Devices • Physical issues between switch and devices • Incorrect storage software configurations • Device LEDs • Storage diagnostic tools • Switch commands (for example, switchShow or nsAllShow) for diagnostics Fabric OS 6.x administrator guide 301