AIX: Capturing Boot Debug

Capturing Boot Debug

Question

Capturing Boot Debug

Answer

This document can be used to assist in capturing boot debug information which may help determine why a system is hanging during IPL.These steps are valid for AIX 5L and AIX 6.1.

HMC environment

Setting up the software

Using SSH session to capture console output

1. Configure an SSH client (eg putty) to log session output to a local file.


2. Open a connection to the HMC and login as user 'hscroot'.


3. Run the command vtmenu.


4. At the vtmenu, select the server to which you desire a console session.


5. Select the LPAR from which you need boot debug.


6. Wait for "Open Completed" message (if LPAR were Running you would get a Console: login)

Booting the HMC to Open Firmware (OK) prompt

1. From a WebSM session, under Server Managment, right click the Partition name and choose 'Activate' from the popup menu.


2. From the Activate Logical Partition popup window, click the "Advanced" button.


3. From the Activate Logical Partition - Advanced popup window, click "Open Firmware OK Prompt" from the Boot Mode drop down list.

Enabling the debug boot image

1. Back in the SSH console session window, wait for the open firmware prompt - "0>"


2. For AIX 5.3 and greater, use:
   At the 0> prompt, enter "boot -s verbose"
   0> boot -s verbose
   
3. For AIX 5.2 or earlier use:
   At the 0> prompt, enter "boot -s trap"
   0> boot -s trap
   
   

   For cdrom boot debug enter: 0> boot cdrom:\ppc\chrp\bootfile.exe -s trap

   At the KDB(0)> prompt, enter the following...
   

    KDB(0)> mw enter_dbg
    enter_dbg+000000:  00000000  = 42
    enter_dbg+000004:  00000000  = .
    KDB(0)>g
    

   At this point, the LPAR will continue to boot and debug information will be sent to the console.

Capturing the debug information

1. The console session is being run via the SSH connection to the HMC and the output will be captured in the log file configured in step 1. Once the system boot fails or hangs, stop the LPAR and send the boot debug log file to IBM Support for review.

Source:
http://www-01.ibm.com/support/docview.wss?uid=isg3T1000628