Chapter 11. Network Installation Management Troubleshooting

This chapter suggests solutions for network boot problems and describes procedures for producing debug output for NIM BOS installations. Refer to Error and Warning Messages and AIX Version 4.3 Messages Guide and Reference for information about error messages.

Debugging a Network Boot Problem

If a client machine is unable to network boot from its boot server, there may be a problem in one or more of the following stages of the network boot:

• Establishing network communication between the client and server
• Obtaining the boot image from the server
• Running the boot image on the client.

The following sections describe steps that can be followed to determine the source of failures during each stage.

Establishing Network Communication Between the Client and Server

1. Before initiating the network boot on the client, perform a ping test from the client bootp menus.
2. If the ping test fails, verify that the client, server, and gateway addresses are specified correctly.
3. If the addresses are correct, try to ping the server from a different machine in the client's subnet.
4. If the server can be pinged from another machine, the network adapter on the boot client may be faulty.
5. If the server cannot be pinged from another machine in the client's subnet, there may be routing problems between the client and the server, or network communications on the server may be faulty. Perform network debugging procedures to determine the source of the problem.

Obtaining the Boot Image from the Server

1. If the ping test is successful, perform a network boot of the client. When a network boot is initiated on a client, a bootp request packet is sent from the client to the server. The server then replies with a packet to the client. The client machine displays the number of packets sent and received for the bootp request. If a packet is sent from the client, but none is received, another packet will be sent.
2. If bootp packets continue to be sent but not received, the boot server may not be responding to the request.
3. From the bootp server, view the /etc/bootptab file on the server. It should contain an entry for the client machine with the following information:

   <hostname of client>
   bf=<boot file>
   ip=<client ip address>
   ht=<network type>
   sa=<boot server address>
   sm=<client subnet mask>
   ha=<network adapter hardware address> (required only if bootp
   requests are sent by broadcasting)

   If an entry does not exist, either the NIM command used to set up the current operation failed, or the machine was reset before the boot operation could occur. Rerun the NIM bos_inst, diag, or maint_boot operation to prepare the server for the client boot request.

   If the entry exists in /etc/bootptab, verify that the specified data is correct. If a field contains incorrect data, the information that was used to define the machine or network in the NIM database was probably wrong. Correct this problem by resetting the client machine, correcting the invalid data in the client or network definition, retrying the NIM operation, and rebooting the client.

4. If the /etc/bootptab file is correct, verify that the inetd daemon is running. If it is not running, start it and retry the network boot from the client. If the inetd daemon is running, it should automatically start the bootpd daemon when the bootp request is received at the server.
5. If the bootpd daemon is not started, verify that the bootps entry in the /etc/inetd.conf file is not commented out. If it is commented out, uncomment it and restart inetd with the refresh -s inetd command. Retry the network boot from the client.
6. If a bootp reply is still not received at the client, manually start the bootpd daemon in debug mode:
   1. Comment out the bootps entry from the /etc/bootptab file on the server.
   2. Stop all running bootpd processes.
   3. Restart inetd using the refresh -s inetd command.
   4. Start bootpd from the command line using the /usr/sbin/bootpd -s -d -d -d command.
7. Retry to network boot from the client. If no output is displayed from the running bootpd command, the client bootp request is not reaching the server. Verify that the addresses specified in the bootp menus are correct. If they are correct, perform network debugging procedures to determine why the packet is not reaching the server.
8. If the server receives the client bootp request, the running bootpd command displays output matching the client data in the /etc/bootptab file. Verify that the specified addresses are correct. This information is sent back to the client in the bootp reply.
9. If the client is still not receiving the bootp reply, perform network debugging procedures to determine why the reply packet is not reaching the client.
10. After the client receives the bootp reply, it will tftp the boot image from the server.
11. The number of tftp packets transferred to the client will be displayed at the client machine.
12. The boot image has been successfully retrieved at the client machine when the LED shows 299 on rs6k-platform machines or when the bottom third of the screen turns gray on other platform machines.
13. If the tftp of the boot image does not complete successfully, the client may be trying to get the wrong boot image. Verify that the client definition in the NIM database shows the correct platform and kernel type. If the data is incorrect, correct it, reset the client machine, rerun the NIM operation, and reboot the client over the network.
14. Verify that the /tftpboot directory on the boot server contains a link with the client name to the correct boot image. If the link does not exist, reset the client machine, rerun the NIM operation, and reboot the client over the network.
15. If the link with the client name is pointing to the correct boot image and the tftp of the boot image does not complete successfully, the boot image may be corrupted. Recreate the boot image by performing a NIM check operation with the force flag on the SPOT. If the client is not an rs6k-platform machine, also make sure the client has the latest version of the firmware installed.

Running the Boot Image on the Client

After the client machine has successfully received the boot image from the server, the most common errors encountered are hangs with the LED showing 608, 611, or 613. Some machines may not have LED displays. Debugging such problems on these machines will require using debug-enabled boot images. For information on building debug boot images, see Producing Debug Output from the BOS Install Program.