HP StorageWorks Fabric OS 6.x administrator guide (5697-7344, March 2008)

Fabric OS 6.x administrator guide 303
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