Redirecting Debug And Error Message Output; Using The Crashinfo File - Cisco 3845 - Security Bundle Router Software Manual

Using the crashinfo File

The no debug all privileged EXEC command disables all diagnostic output. Using the no debug all
command is a convenient way to ensure that you have not accidentally left any debug commands
enabled.

Redirecting Debug and Error Message Output

By default, the network server sends the output from debug commands and system error messages to the
console. If you use this default, you can use a virtual terminal connection to monitor debug output
instead of connecting to the console port.
Possible destinations include the console, virtual terminals, internal buffer, and UNIX hosts running a
syslog server. The syslog format is compatible with 4.3 Berkeley Standard Distribution (BSD) UNIX
and its derivatives.
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 logging to an internal buffer
produces the least overhead of any method.
For more information about system message logging, see
Logging."
Using the crashinfo File
The crashinfo file saves information that helps Cisco technical support representatives to debug
problems that caused the Cisco IOS 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 next time you boot the Cisco IOS image after
the failure (instead of while the system is failing).
The information in the 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.
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 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 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 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.
Cisco ME 3800X and 3600X Switch Software Configuration Guide
35-14
Chapter 35
Chapter 24, "Configuring System Message
Troubleshooting
OL-23400-01