IBM Link: Recovery from an LED 553 in AIX

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Recovery from an LED 553 in AIX

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This document describes a procedure to attempt to recover from an IPL hang at LED 553.

About LED 553
Recovery procedure
Sample /etc/inittab file for AIX Versions 5 and 6
Sample /etc/environment file for AIX.


About LED 553

An LED value of 553 is a checkpoint code displayed to indicate the system transition to phase 3 of IPL. A halt or hang at LED 553 is often the result of a corrupted or missing /etc/inittab file. It can also be caused by full / (root) or /tmp file systems, inconsistencies in either startup configuration files, Object Data Manager (ODM) object class databases, or system library files. Additionally, a number of other issues involving file permissions, invalid hard links in the root file system, etc. have been observed to cause a hang at LED 553.

Summary of the recovery procedure

To attempt to isolate the cause for an LED 553 hang, start by checking the root file systems with the fsck command. Then check/dev/hd3 and /dev/hd4 for space problems, and erase files if necessary. Check the /etc/inittab file for corruption, and fix it if necessary. If the inittab file was not corrupted, you will need to check the shell profile and environment files, the /bin/bsh file, as well as other system configuration files. A check of the consistency of all installed files within the installed fileset base and an update of the boot image should be done. To conclude, run the configuration manager to find out if there is a hang during device configuration.


Recovery procedure

  1. Boot your system into a limited function maintenance shell (Service or Maintenance mode) from AIX bootable media.Please refer to your system user’s or installation and service guide for specific IPL procedures related to your type and model of hardware. You can also refer to the document titled “Booting in Service Mode”, available at http://techsupport.services.ibm.com/server/aix.srchBroker for more information.
  2. With bootable media of the same version and level as the system, boot the system. The bootable media can be any ONE of the following:
    • Bootable CD-ROM
    • mksysb
    • Bootable Install Tape

    Follow the screen prompts to the Welcome to Base OS menu.

  3. Choose Start Maintenance Mode for System Recovery (Option 3). The next screen contains prompts for the Maintenance menu.
    1. Choose Access a Root Volume Group (Option 1).The next screen displays a warning that indicates you will not be able to return to Base OS menu without rebooting.
    2. Choose 0 continue.The next screen displays information about all volume groups on the system.
    3. Select the root volume group by number. The logical volumes in rootvg will be displayed with two options below.
    4. Choose Access this volume group and start a shell before mounting file systems (Option 2).

    If you get errors from the preceding option, do not continue with the rest of this procedure. Correct the problem causing the error. If you need assistance correcting the problem causing the error, contact one of the following:

    • local branch office
    • your point of sale
    • your AIX support center

    If no errors occur, proceed with the following steps.

  4. Run the following series of commands to check and repair file systems.
     fsck -p /dev/hd4
     fsck -p /dev/hd2
     fsck -p /dev/hd3
     fsck -p /dev/hd9var
     fsck -p /dev/hd1
    

    NOTE: The -y option gives the fsck command permission to repair file system corruption when necessary. This flag can be used to avoid having to manually answer multiple confirmation prompts, however, use of this flag can cause permanent data loss in some situations.

  5. To format the default jfslog for the rootvg Journaled File Systems (JFS), run the following command:
     /usr/sbin/logform /dev/hd8
    

    Answer yes when asked if you want to destroy the log.

  6. Type exit to exit from the shell. The file systems should automatically mount after you type exit. If you receive error messages at this point, reboot into a limited function maintenance shell again to attempt to address the failure causes.
  7. Use the df command to check for free space in /dev/hd3 and /dev/hd4.
       df  /dev/hd3
       df  /dev/hd4
    
  8. If the output from the df command shows that either file system is out of space, erase some files from that file system. Three files you may want to erase are /smit.log, /smit.script and /.sh_history.
  9. Next, check the /etc/inittab file for corruption. It may be empty or missing, or it may have an incorrect entry. For comparison, see the section “Sample /etc/inittab file” at the end of this document.
  10. If the inittab file is corrupt, set your terminal type in preparation for editing the file. (xxx stands for a terminal type, such as lft, ibm3151, or vt100.)
       TERM=xxx
       export TERM
    

    Now use an editor to create the /etc/inittab file. For an example, see the section “Sample /etc/inittab file” in this document. If your /etc/inittab file was corrupt and you recreated it, the following steps may not be necessary.

    There are only three entries which must be in the /etc/inittab file to successfully boot the system. If your /etc/inittab file is missing or corrupted AND you are unable to use an editor while in Service mode, do the following to create a minimal inittab file to boot the machine into run level 2 (Normal mode).

      mv /etc/inittab /etc/inittab.MMYYDD
      touch /etc/inittab
      chmod 544 /etc/inittab
      chown root:system /etc/inittab
      echo 'init:2:initdefault:' >> /etc/inittab
      echo 'brc::sysinit:/sbin/rc.boot 3 >/dev/console 2>&1' >> /etc/inittab
      echo 'cons:0123456789:respawn:/usr/sbin/getty /dev/console' >> /etc/inittab
    

    MMDDYY represents the current two-digit representation of the Month, Day and Year respectively.

  11. Use the following command to check for any modifications or problems with permissions on shell startup files.NOTE: The /.kshrc and /.profile files are not necessary for the system to boot into run level 2 (Normal mode) and, in fact, may not exist on your system.
       ls -al /.kshrc /.profile /etc/environment /etc/profile
    

    Sample output:

    -rw-r--r--  1 root  system   71 Dec 14 1993  /.kshrc
    -rw-r--r--  1 root  system  158 Dec 14 1993  /.profile
    -rw-rw-r--  1 root  system 1389 Oct 26 1993  /etc/environment
    -rw-r-xr-x  1 bin   bin    1214 Jan 22 1993  /etc/profile
    

    etc/profile or .profile may contain a command that is valid only in the Korn shell. Change the command to something that is also valid in the Bourne shell. For example, change the following:

       export PATH=/bin:/usr/bin/:/etc:/usr/ucb:.
    

    to the following:

       PATH=/bin:/usr/bin/:/etc:/usr/ucb:.
       export PATH
    

    /etc/environment is a special case. The only commands it may contain are simple variable assignments, such as statements of the form (varname)=(value). Check this file with an editor to verify the format. See the section “Sample /etc/environment file” at the end of this document.

  12. Check for missing or moved files, or changed ownership/permissions with the following command:
       ls -al /bin /bin/bsh /bin/sh /lib /unix /u
    

    Sample output:

    lrwxrwxrwx 1 bin  bin       8 Aug 5 1994 /bin -> /usr/bin
    -r-xr-xr-x 3 bin  bin 25622 4 Jun 4 1993 /bin/bsh
    -r-xr-xr-x 3 bin  bin 25622 4 Jun 4 1993 /bin/sh
    lrwxrwxrwx 1 bin  bin       8 Aug 5 1994 /lib -> /usr/lib
    lrwxrwxrwx 1 bin  bin       5 Aug 5 1994 /u -> /home 
    lrwxrwxrwx 1 root system    18 Aug 5 1994 /unix -> /usr/lib/boot/unix
    

    If any of these files are missing, the problem may be a missing symbolic link. Use the commands from the following list that correspond to the missing links.

       ln -s /usr/bin /bin
       ln -s /usr/lib/boot/unix /unix
       ln -s /usr/lib /lib
       ln -s /home /u
    
  13. Use the following command to make sure that rc.boot is not missing or corrupt.
       ls -l /sbin/rc.boot
    

    Sample output:

    -rwxrwxr-- 1 root system 33760 Aug 30 1993 /sbin/rc.boot
    
  14. Make sure the /etc/inittab file is for AIX Version 5 or 6. For these versions, the line that begins with brc is
       brc::sysinit:/sbin/rc.boot 3 >/dev/console 2>&1
    

    See the section “Sample /etc/inittab file” in this document for an example.

  15. If you have not found any obvious problems, try substituting ksh for bsh with the following series of commands. (The first command saves your bsh before you copy over it.)
       cp /bin/bsh /bin/bsh.orig
       cp /bin/ksh /bin/bsh
    

    If you can then reboot successfully, this indicates that one of the profiles was causing problems for bsh. Check the profiles again by running the following:

       /bin/bsh.orig /.profile
       /bin/bsh.orig /etc/profile
       /bin/bsh.orig /etc/environment
    

    If you receive errors with any of the preceding commands, this indicates that there is a command in that profile that bsh cannot handle.

  16. To run a checksum validation of all files in the installed fileset base and a consistency check of the fileset installation, run the following commands:
     lppchk -c
     lppchk -v
            lppchk -l
    

    NOTE: These commands should not produce output. If they do, then the messages should be examined to assess whether it is a potential cause of the hang.

  17. Detemine the boot drive and update the boot image with the following command:
     lslv -m hd5
    

    Sample output:

       hd5:N/A
       LP    PP1  PV1               PP2  PV2               PP3  PV3
       0001  0001 hdisk0
    

    The disk number under the PV1 column is the disk name you should use to run the following two commands:

     bosboot -ad /dev/hdisk0
     bootlist -m normal hdisk0
    
  18. To check the device configuration routines, the following command should identify any problems associated with configuration routines:
     cfgmgr -vp 2
    

    If the cfgmgr command hangs, this is likely the cause of the system hang. You may be able to stop the command by pressing Ctrl-C, however, a reboot is often required to get back into Service mode and continue troubleshooting the problem.

  19. If your model has a mode select key, turn it to the Normal position.
  20. Attempt to reboot the system into Normal mode by running the following command:
     sync;sync;sync;reboot
    

If you followed all of the preceding steps and the system still stops at an LED 553 during a reboot in Normal mode, you may want to consider reinstalling your system from a recent backup. Isolating the cause of the hang could be excessively time-consuming and may not be cost-effective in your operating environment. To isolate the possible cause of the hang, would require a debug boot of the system. Instructions for doing this are included in the document, “Capturing Boot Debug”, available at http://techsupport.services.ibm.com/server/aix.srchBroker. It is still possible, in the end, that isolation of the problem may indicate a restore or reinstall of AIX is necessary to correct it.

If you wish, you may pursue further system recovery assistance from one of the following:

  • local branch office
  • your point of sale
  • your AIX support center

Sample /etc/inittab file for AIX Versions 5 and 6

:  US Government Users Restricted Rights - Use, duplication or
:  disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
:
: Note - initdefault and sysinit should be the first and second entry.
:
init:2:initdefault:
brc::sysinit:/sbin/rc.boot 3 >/dev/console 2>&1 # Phase 3 of system boot
powerfail::powerfail:/etc/rc.powerfail 2>&1 | alog -tboot > /dev/console # Power
 Failure Detection
load64bit:2:once:/etc/methods/cfg64 >/dev/console 2>&1 # Enable 64-bit execs
rc:2:wait:/etc/rc 2>&1 | alog -tboot > /dev/console # Multi-User checks
fbcheck:2:wait:/usr/sbin/fbcheck 2>&1 | alog -tboot > /dev/console # run /etc/fi
rstboot
srcmstr:2:respawn:/usr/sbin/srcmstr # System Resource Controller
rctcpip:2:wait:/etc/rc.tcpip > /dev/console 2>&1 # Start TCP/IP daemons
rcnfs:2:wait:/etc/rc.nfs > /dev/console 2>&1 # Start NFS Daemons
cron:2:respawn:/usr/sbin/cron
piobe:2:wait:/usr/lib/lpd/pio/etc/pioinit >/dev/null 2>&1  # pb cleanup
uprintfd:2:respawn:/usr/sbin/uprintfd
logsymp:2:once:/usr/lib/ras/logsymptom # for system dumps
pmd:2:wait:/usr/bin/pmd > /dev/console 2>&1 # Start PM daemon
diagd:2:once:/usr/lpp/diagnostics/bin/diagd >/dev/console 2>&1
dt:2:wait:/etc/rc.dt
cons:0123456789:respawn:/usr/sbin/getty /dev/console

Sample /etc/environment file for AIX Versions 5 and 6

# @(#)18        1.21  src/bos/etc/environment/environment, cmdsh, bos430, ...
PATH=/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/sbin:/local/netscape:/usr/lo
cal/bin
TZ=CST6CDT
LANG=en_US
LOCPATH=/usr/lib/nls/loc
MOZILLA_HOME=/local/netscape
export MOZILLA_HOME
NLSPATH=/usr/lib/nls/msg/%L/%N:/usr/lib/nls/msg/%L/%N.cat
LC__FASTMSG=true
PS1='MYSYSTEM $PWD=>'
set -o vi
# ODM routines use ODMDIR to determine which objects to operate on
# the default is /etc/objrepos - this is where the device objects
# reside, which are required for hardware configuration
ODMDIR=/etc/objrepos
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