Kernel Extensions and Device Support Programming Concepts

Starting a System Dump

A user-initiated dump is different from a dump initiated by an unexpected system halt because the user can designate which dump device to use. When the system halts unexpectedly, a system dump is initiated automatically to the primary dump device.

You can start a system dump by using one of the methods listed below.

You have access to the sysdumpstart command and can start a dump using one of these methods:

• Using the Command Line
• Using SMIT
• Using the Reset Button
• Using Special Key Sequences

Using the Command Line

Use the following steps to choose a dump device, initiate the system dump, and determine the status of the system dump:

1. Check which dump device is appropriate for your system (the primary or secondary device) by using the following sysdumpdev command:

   sysdumpdev -l

   This command lists the current dump devices. You can use the sysdumpdev command to change device assignments.

2. Start the system dump by entering the following sysdumpstart command:

   sysdumpstart -p

   This command starts a system dump on the default primary dump device. You can use the -s flag to specify the secondary dump device.

3. If a code shows in the operator panel display, refer to Checking the Status of a System Dump. If the operator panel display is blank, the dump was not started. Try again using the Reset button.

Using SMIT

Use the following SMIT commands to choose a dump device and start the system dump:

1. Check which dump device is appropriate for your system (the primary or secondary device) by using the following SMIT fast path command:

   smit dump

2. Choose the Show Current Dump Devices option and write the available devices on notepaper.
3. Enter the following SMIT fast path command again:

   smit dump

4. Choose either the primary (the first example option) or secondary (the second example option) dump device to hold your dump information:

   Start a Dump to the Primary Dump Device

   OR

   Start a Dump to the Secondary Dump Device

   Base your decision on the list of devices you made in step 2.

5. Refer to Checking the Status of a System Dump if a value shows in the operator panel display. If the operator panel display is blank, the dump was not started. Try again using the Reset button.
   Note
   To start a dump with the reset button or a key sequence you must have the key switch, or mode switch, in the Service position, or have set the Always Allow System Dump value to true. To do this:

   1. Use the following SMIT fast path command:

      smit dump

   2. Set the Always Allow System Dump value to true. This is essential on systems that do not have a mode switch.

Using the Reset Button

Start a system dump with the Reset button by doing the following (this procedure works for all system configurations and will work in circumstances where other methods for starting a dump will not):

1. Turn your machine's mode switch to the Service position, or set Always Allow System Dump to true.
2. Press the Reset button.

Your system writes the dump information to the primary dump device.

Using Special Key Sequences

Start a system dump with special key sequences by doing the following:

1. Turn your machine's mode switch to the Service position, or set Always Allow System Dump to true.
2. Press the Ctrl-Alt 1 key sequence to write the dump information to the primary dump device, or press the Ctrl-Alt 2 key sequence to write the dump information to the secondary dump device..