Apple 10.6 manual Setting Up a Core Dump Client, Setting up a core dump client

Setting Up a Core Dump Client

A core dump client sends its kernel panic debug information to the core dump server address specified in its NVRAM settings.

The information is transmitted at the time of the panic, so before restarting the computer, allow some time for the data to be sent to the server. The time necessary depends on the file size of the core dump and the speed of the network connection between the client and server.

For clients using v10.5 or earlier, see developer.apple.com/technotes/tn2004/tn2118.html.

Setting up a core dump client:

1Modify the “boot-args” NVRAM variable to include the “debug” flag 0x0400, and the “_panicd_ip” flag with the IP address of the core dump server.

The following example uses the core dump server IP address 192.168.1.250. Substitute the IP address of your own core dump server.

sudo nvram boot-args="debug=0x0400 _panicd_ip=192.168.1.250"

Important: You can reset the boot-args NVRAM variable whenever you install new system software, including software updates, and when you change the startup disk using System Preferences.

2If the core dump client is running Mac OS X Server, modify the watchdogtimerd behavior to either keep it from restarting the server before the core dump is complete, or modify the amount of time it waits before restarting the server.

To disable automatic restarting, turn off the “Restart automatically after a power failure” option in the Options tab of the Energy Saver System Preferences pane.

To increase the amount of time before automatic restarting, add a “count” program argument larger than 6 (but smaller than 480) to the watchdogtimerd configuration file at /System/Library/LaunchDaemons/com.apple.watchdogtimerd.plist.

For more information about the arguments and options, see the watchdogtimerd(8) man page.

3Restart the computer for the settings to take effect.

For additional NVRAM debug flags that are useful in core dump debugging, see Developer Technical Note #2118, subsection “Debug Flags in Depth,”at developer.apple.com/technotes/tn2004/tn2118.html

Chapter 8    Monitoring Your System

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