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Booting in Service Mode

This document describes how to boot the system into Service mode (also known as Maintenance mode) to install the machine, restore an operating system backup, or perform maintenance on the rootvg volume group.

The information in this document applies to all Versions of AIX.

Booting microchannel systems into Service mode
Booting PCI-based systems into Service mode
PCI machine-specific information
Accessing rootvg and mounting file systems
Known problems
Related documentation

Booting microchannel systems into Service mode

To boot microchannel systems into Service mode, turn the key to the Maintenance position and press the yellow reset button twice. You must boot from bootable media, such as an installation CD-ROM, installation tape, or a bootable backup tape made via the mksysb command or the Sysback product of the correct level for this machine.

For AIX Version 3.2, you may use bootable bosboot diskettes. To boot from these, insert the first bosboot diskette into the diskette drive. When you see LED c07, insert the next diskette, which is usually the display extensions diskette. After this diskette is read, you should receive a menu prompting you for the installation diskette.

For information on accessing your rootvg volume group, see the section entitled "Accessing rootvg and mounting file systems".

The preceding discussion assumes that the Service mode bootlist has not been modified from the default bootlist. If the bootlist has been modified, it must be reset such that one of the boot media types from the preceding selections is before the standard boot media, such asthe hard disk.

If the machine is an SMP model (7012-Gxx, 7013-Jxx, and 7015-Rxx) and the Autoservice IPL flag is disabled, then a menu like the following will display when it is booting in Service mode:

                         MAINTENANCE MENU (Rev. 04.03)
                       0> DISPLAY CONFIGURATION
                       1> DISPLAY BUMP ERROR LOG
                       2> ENABLE SERVICE CONSOLE
                       3> DISABLE SERVICE CONSOLE
                       4> RESET
                       5> POWER OFF
                       6> SYSTEM BOOT
                       7> OFF-LINE TESTS
                       8> SET PARAMETERS
                       9> SET NATIONAL LANGUAGE

You can boot these machines into Service mode or even Normal mode with the Fast IPL Flag set. If you do not, the machine can take anywhere from 30 to 60 minutes to boot up. There are a few ways to set the Fast IPL Flag for these machines.

NOTE: The console must be an ASCII type and connected to the S1 port of the system. Graphic monitors will not work.

Use the following instructions to boot SMP machines into service with Fast IPL set.

  1. Insert the bootable media of the same OS Level. Use the mksysb/cd-rom command.
  2. Turn off the machine by pressing the white button on front.
  3. Turn the key to the Wrench or Service position.
  4. The LCD should read STAND-BY.
  5. Press the Enter key on the console.
  6. A greater-than prompt (>) should display on the monitor.
  7. Type in sbb followed by the Enter key.
  8. The menu Stand By Menu should now display.
  9. Select 1 Set Flags. This will take you to another set of menus.
  10. Select 6 Fast IPL. This should change to enable after it is selected.
  11. Enter x to exit the second set of menus.
  12. Enter x to exit the first menu.
  13. At a blank screen, press the Enter key to obtain the greater-than prompt (>).
  14. Type in the word power followed by the Enter key.
  15. Turn the machine back on. It should start to boot up. A prompt may display asking if you want to update the firmware. Do not respond; let it continue.
  16. Now you may be at the Maintenance Menu with 10 options displayed, 0 through 9. If that is the case, select option 6, System Boot. This will take you to another menu. Select option 0, Boot from the list.
  17. The Standard Maintenance Menu should display. System recovery and maintenance can be completed from here.
  18. After system recovery and maintenance has been performed, the system is ready to be rebooted into Normal mode. Enter the command mpcfg -cf 11 1 at the command line prompt, then press Enter. This will set the Fast IPL Flag. The system is ready to reboot.
  19. Turn the key back to the OK/Normal position.
  20. Enter shutdown -Fr, followed by the Enter key.

Booting PCI-based systems into Service mode

When booting a PowerPC into Service mode, cd0 or rmt0 must be before the hdisk in the bootlist. If not, change the bootlist at boot time. On some models, you can set the machine to use a default bootlist that includes both cd0 and rmt0. If a bootable CD or tape is in the CD-ROM or tape drive, the machine will boot from this device.

For most of the newer PCI-based models, selecting the default bootlist, with a bootable tape or CD loaded in the machine, causes the system to automatically boot from that device. Generally, the next menu on the screen asks the administrator to define the system console.

For all machines discussed here, if you are using a graphical terminal, you will use a function key such as F5. If you are using an ASCII terminal, use an equivalent number key such as 5. Use the numbers across the top of the keyboard, not the numbers on the numeric keypad. On ASCII terminals, the icons may not be displayed on the screen; the number can be pressed between the second and third beeps, the second beep being a series of three clicks.

PCI machine-specific information

The following systems all use the F5 or 5 key to read from the default boot list, which is written into the system firmware:

MODEL       7017       7024       7025       7026       7043       7137
-------   -------    -------    -------    -------    -------    -------
TYPE      S70        E20        F30        H10        43P-140    F3L
          S7A        E30        F40        H50        43P-150        
          S80                   F50        H70        43P-240           
                                           B80        43P-260          

On these machines, use 5 (on the keyboard, not the keypad) if you are using an ASCII terminal. On a locally attached graphics console, use the F5 function key. The F5 or 5 key must be pressed just after the keyboard icon or message is displayed on the console. If you have either a 7026-M80, 7026-H80 or a 7025-F80, then the 5 key will be the default whether you have an ascii or graphics console.

The following systems use the F1 key to enter System Management Services mode (SMS):

MODEL       6040       7042       7247       7249
-------   -------    -------    -------    -------
TYPE        620        850        82x        860

You should be in an Easy-Setup menu. Select the Start Up menu. Clear the current bootlist settings and then select the CD-ROM for choice 1 and hdd (the hard disk) for choice 2. Select OK. Insert the CD-ROM and select the EXIT icon. The machine should now boot from the CD-ROM.

The following systems use the F2 key to enter SMS:

MODEL         6015       6050       6070       7020       7248
-------     -------    -------    -------    -------    -------
TYPE          440        830        850        40P        43P

Select Select Boot Device from the initial menu on the screen, and then select Restore Default Settings from the list. Press the Esc key to exit all the menus, and then reboot the machine. The system should boot from your bootable media.

For information on accessing the rootvg volume group, see the next section in this document.

Accessing rootvg and mounting file systems

For AIX Version 3, choose the limited function maintenance shell (option 5 for AIX 3.1, option 4 for AIX 3.2).

If you only have one disk on the system, then hdisk0 will be used in the execution of the getrootfs or /etc/continue commands, which follow. If you have more than one disk, determine which disk contains the boot logical volume in this manner:

AIX 3.2.4 or AIX 3.2.5:

Run getrootfs; the output will indicate which disk contains the hd5 logical volume.

AIX 3.1 to AIX 3.2.3e:

Run lqueryvg -Ltp hdisk# for each hdisk. You can obtain a listing of these with the command lsdev -Cc disk. Repeat this command until you get output similar to the following:

             00005264feb3631c.2  hd5  1
If more than one disk contains this output, use any disk when running getrootfs.

Now, access the rootvg volume group by running one of the following commands, using the disk you obtained in the preceding step:

    AIX 3.1:                     /etc/continue hdisk#
    AIX 3.2.0-3.2.3e:            getrootfs -f hdisk#
    AIX 3.2.4-3.2.5:             getrootfs hdisk#

NOTE: If you want to leave the primary OS file systems (/, /usr, /tmp, and /var) unmounted after this command has completed, to run fsck, for instance, place a space and the letters sh after the hdisk in the preceding command. For example:

    getrootfs hdisk0 sh
For AIX Versions 4 and 5, choose Start Maintenance Mode for System Recovery , option 3. The next screen will be called Maintenance; select option 1, Access a Root Volume Group. At the next screen, type 0 to continue, and select the appropriate volume group by typing the number next to it. A screen like the following will display.


                           Access a Root Volume Group

Type the number for a volume group to display the logical volume information and press Enter.

  1)  Volume Group 0073656f2608e46a contains these disks:
      hdisk0  2063 04-C0-00-4,0

Once a volume group has been selected, information will be displayed about that volume group.


                           Volume Group Information
    Volume Group ID 0073656f2608e46a includes the following logical volumes:
         hd6         hd5         hd8         hd4         hd2      hd9var
         hd3         hd1        

Type the number of your choice and press Enter.

   1) Access this Volume Group and start a shell
   2) Access this Volume Group and start a shell before mounting filesystems
  99) Previous Menu

If the logical volumes listed do not include logical volumes like hd4, hd2, hd3, and so on, you may have selected the wrong volume group. Press 99 to back up one screen and select again.

Now you may select one of two options: Access this volume group and start a shell , option 1, or Access this volume group and start a shell before mounting file systems , option 2. Option 2 allows you to perform file system maintenance on /, /usr, /tmp, and /var before mounting them.

NOTE: If you intend to use SMIT or vi, set your terminal type in preparation for editing the file. xxx stands for a terminal type such as lft, ibm3151, or vt100.

        export TERM

Errors from these steps may indicate failed or corrupt disks in rootvg. These problems should be corrected. For additional assistance, contact your vendor, your local branch office, or your AIX support center.

Known problems

NOTE: Ensure you are using an original AIX base media to boot from, rather than a burned copy.

You may receive the following error when trying to access rootvg in service mode at AIX 5.1:

Examine .loader section symbols with the 'dump -Tv' command. 
Could not load program /usr/bin/ksh: Symbol resolution failed for /usr/lib/libc.a (shr.o) 
because: OID Symbol getvtid (number 258) is not exported from dependent RS4 
module /unix.

This error is likely due to a mismatch of the boot media and the system's AIX level.


Use a non-auto install mksysb from the same system, or use AIX CD media labeled LCD4-1061-04 or higher (9/23/2002, integranted ML03)

Related documentation

For more in-depth coverage of this subject, the following IBM publication is recommended:
AIX Version 4.3 System Management Guide: Operating System and Devices
AIX Version 5.1 System Management Guide: Operating System and Devices

 Document information
 Product categories:
 Operating System
 Installation, backup, restore
 Operating system(s):
 Software Version:
  4.1, 4.2, 4.3, 5.1, 5.2
 Reference #:
 IBM Group:
 IBM Server Group
 Modified date:

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