Technical data

Fabric OS Administrator’s Guide 10-1
Publication Number: 53-0000518-09
Chapter
10
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 (such as switchShow) to
find out if the storage device is logically connected to the switch. If not, focus first on the switch
directly connecting to storage. Use your vendor-supplied storage diagnostic tools 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.
This chapter provides information on troubleshooting and the most common procedures used to
diagnose and repair issues. It also includes specific troubleshooting scenarios as examples.
Most Common Problem Areas
Refer to Table 10-1 for a list of the most common problem areas that arise within SANs and a list of
tools that can be used to resolve them.
Table 10-1 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