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Catalyst 2940 Switch Software Configuration Guide
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Chapter26 Troubleshooting Using the crashinfo File
Note Be aware that the debugging destination you use affects system overhead. Logging messages to the
console produces very high overhead, whereas logging messages to a virtual terminal produces less
overhead. Logging messages to a syslog server produces even less, and lo ggi ng t o an int ern al buffer
produces the least overhead of any method.
For more information about system message logging, see Chapter22, “Configuring System Messa ge
Logging.”
Using the crashinfo File
The crashinfo file saves information that helps Cisco technical support representatives to debug
problems that caused the software image to fail (crash). The switch writes the crash information to the
console at the time of the failure, and the file is created the nex t time you bo ot the image after the failu re
(instead of while the system is failing).
The information in the file includes the software image name and version that failed, a dump of the
processor registers, and a stack trace. You can give this information to the Cisco technical support
representative by using the show tech-support privileged EXEC command.
All crashinfo files are kept in this directory on the Flash file system:
flash:/crashinfo/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-existin g
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 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.