HP AE370A - Brocade 4Gb SAN Switch 4/12, Administrator'S Manual

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Fabric OS 5.2.x administrator guide 281
15 Troubleshooting
This chapter provides information on troubleshooting and the most common procedures used to diagnose
and recover from problems. It also includes specific troubleshooting scenarios as examples.
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.
Most common problem areas
Refer to Table 57 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 57 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
Hosts • Downlevel HBA firmware
• Incorrect device driver installation
• Incorrect device driver configuration
• Use the latest HBA firmware
recommended by the switch
supplier or on the HBA supplier's
web site
• 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