HP StorageWorks Fabric OS 5.X Administrator Guide (AA-RVHWB-TE, September 2005)

Fabric OS 5.x administrator guide 143
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, determine
whether 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 whether the storage device is logically connected to the switch. If not, focus first on the switch
directly connecting to the storage device. Use your vendor-supplied storage diagnostic tools to better
understand why the storage device is not visible to the switch. If the storage device can be detected by the
switch, and the host still cannot detect the storage device, 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
See Table 23 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 23 Common troubleshooting problems and tools
Problem area Items to 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
Hosts
• Incorrect host bus adapter
installation
• Incorrect device driver
installation
• Incorrect device driver
configuration
• Host adaptor LEDs
• Host operating system
diagnostic tools
• Device driver diagnostic tools
• Switch commands (for example,
switchShow or nsAllShow)
for diagnostics
Storage management
applications
Incorrect installation and
configuration of the storage devices
that the software references.
For example, if using a
volume-management application,
check for:
• Incorrect volume installation
• Incorrect volume
configuration
Application-specific tools and resources