unixadmin.free.fr Handy Unix Plumbing Tips and Tricks

Producing debug output from a network boot image

Use these commands to create debug versions of the network boot images.

1. Use the Web-based System Manager or SMIT interfaces or run the following command:

where SPOTName is the name of your SPOT.

2. Obtain the address for entering the debugger by doing the following:

where SPOTName is the name of your SPOT. The displayed output will be similar to the following:

Write down the enter_dbg address for the client you are going to boot. For example, if your client is an chrp-uniprocessor machine, you would write down the address 160b7c.

3. Attach a tty device to your client system (port 1).

4. Set up and perform the NIM operation that will require the client to boot over the network. Boot the client over the network.

5. After the client gets the boot image from the SPOT server, the debug screen will appear on the tty. At the > prompt, enter:

where Enter_dbg_Value is the number you wrote down in step 2 as your machine type's enter_dbg value. Specifying a 2 at the address of the enter_dbg value prints the output to your tty.

6. Type g (for go) and press Enter to start the boot process.

7. Use Ctrl-s to temporarily stop the process as you watch the output on the tty. Use Ctrl-q to resume the process.

8. To rebuild your boot images in non-debug mode, use the following command:

where SPOTName is the name of your SPOT.

If the boot image is left in debug mode, every time a client is booted from these boot images, the machine will stop and wait for a command at the debugger ">" prompt. If you attempt to use these debug-enabled boot images and there is not a tty attached to the client, the machine will appear to be hanging for no reason.