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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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Chapter 51 Troubleshooting Using On-Board Failure Logging

Basic crashinfo Files

The information in the basic file includes the Cisco IOS image name and version that failed, a list of the
processor registers, and a stack trace. You can provide this information to the Cisco technical support
representative by using the show tech-support privileged EXEC command.
Basic crashinfo files are kept in this directory on the flash file system:
flash:/crashinfo/.
The filenames are crashinfo_n where n is a sequence number.
Each new crashinfo file that is created uses a sequence number that is larger than any previously existing
sequence number, so the file with the largest sequence number describes the most recent failure. Version
numbers are used instead of a timestamp because the switches do not include a real-time clock. You
cannot change the name of the file that the system will use when it creates the file. However, after the
file is created, you can use the rename privileged EXEC command to rename it, but the contents of the
renamed file will not be displayed by the show stacks or the show tech-support privileged EXEC
command. You can delete crashinfo files by using the delete privileged EXEC command.
You can display the most recent basic crashinfo file (that is, the file with the highest sequence number
at the end of its filename) by entering the show stacks or the show tech-support privileged EXEC
command. You also can access the file by using any command that can copy or display files, such as the
more or the copy privileged EXEC command.

Extended crashinfo Files

The switch creates the extended crashinfo file when the system is failing. The information in the
extended file includes additional information that can help determine the cause of the switch failure. You
provide this information to the Cisco technical support representative by manually accessing the file and
using the more or the copy privileged EXEC command.
Extended crashinfo files are kept in this directory on the flash file system:
flash:/crashinfo_ext/.
The filenames are crashinfo_ext_n where n is a sequence number.
You can configure the switch to not create the extended creashinfo file by using the no exception
crashinfo global configuration command.
Using On-Board Failure Logging
You can use the on-board-failure logging (OBFL) feature to collect information about the switch. The
information includes uptime, temperature, and voltage information and helps Cisco technical support
representatives to troubleshoot switch problems. We recommend that you keep OBFL enabled and do
not erase the data stored in the flash memory.
• Understanding OBFL, page 51-26
• Configuring OBFL, page 51-26
• Displaying OBFL Information, page 51-27