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Troubleshooting LED Code 0c61 while booting from a restored disk using alt_disk_mksysb.

Troubleshooting


Problem

There are scenarios where the customer took an mksysb from the source LPAR with PP Size 32 MB, migrated the mksysb to a higher version using nimadm, and then restored the migrated mksysb using alt_disk_mksysb, but later booting from the alternate disk failed with LED Code 0c61.

 

Cause

alt_disk_mksysb writes the boot images into the target disk. The system performs an additional reboot when booting from the alternate rootvg for the first time, and the bootimage size may increase. Therefore, bosboot will fail when the size of the boot image is over 32MB boot logical volume.

Environment

AIX

 

Diagnosing The Problem

The source system is running AIX 7.1  with a 32 MB PP size. 
 
# oslevel -s
7100-05-10-2220

# lsvg rootvg
VOLUME GROUP:       rootvg                   VG IDENTIFIER:  00fa845200004b000000018e7b0c399d
VG STATE:           active                   PP SIZE:        32 megabyte(s)
VG PERMISSION:      read/write               TOTAL PPs:      799 (25568 megabytes)

# lsvg -l rootvg
rootvg:
LV NAME             TYPE       LPs     PPs     PVs  LV STATE      MOUNT POINT
hd5                 boot       1       1       1    closed/syncd  N/A
The mksysb taken from the source system is then migrated to AIX 7.2 using nimadm and restored to an alternate disk using alt_disk_mksysb method. 
  
# cd /mksysb
# ls -lrt
total 2959024
drwxr-xr-x    2 root     system          256 Mar 26 09:27 lost+found
-rw-------    1 root     system   1515008000 Mar 26 23:25 opslab172_7200
#
# lsmksysb -lf opslab172_7200
VOLUME GROUP:           rootvg
BACKUP DATE/TIME:       Tue Mar 26 09:49:19 CDT 2024
UNAME INFO:             AIX opslab172 1 7 00FA84524B00
BACKUP OSLEVEL:         7.2.5.3
MAINTENANCE LEVEL:      7200-05
SERVICEPACK LEVEL:      7200-05-06-2320
BACKUP SIZE (MB):       4704
SHRINK SIZE (MB):       3875
VG DATA ONLY:           no
Booting from the restored disk fails with LED code 0c61, and the boot debug from the migrated disk shows following error.
  
​​​​​​​Error: the boot image is corrupted or truncated.
Use alternative media or recovery procedures.

Resolving The Problem

First, restore the image.data from the migrated mksysb, edit LP and PP, and then use the customized image data to restore.
  
# cd /mksysb
# ls -lrt
total 2959024
drwxr-xr-x    2 root     system          256 Mar 26 09:27 lost+found
-rw-------    1 root     system   1515008000 Mar 26 23:25 opslab172_7200
# restore -xqvf opslab172_7200 ./image.data
New volume on opslab172_7200:
Cluster size is 51200 bytes (100 blocks).
The volume number is 1.
The backup date is: Tue Mar 26 09:49:21 CDT 2024
Files are backed up by name.
The user is root.
x        10650 ./image.data
The total size is 10650 bytes.
The number of restored files is 1.

# ls
image.data      lost+found      opslab172_7200
Rename the image.data file and change the LPs and PPs to 2 for hd5.
  
# mv image.data cust_image.data
# vi cust_image.data
...snip...
lv_data:
        VOLUME_GROUP= rootvg
        LV_SOURCE_DISK_LIST= hdiskX
        ...
        LOGICAL_VOLUME= hd5
        ...
        LPs= 2
        ...
        PP= 2
        ...

Now restore the mksysb using the custom image data.
  
# alt_disk_mksysb -m /mksysb/opslab172_7200 -d hdisk1 -i /mksysb/cust_image.data
Restoring /image.data from mksysb image.
Checking disk sizes.
Creating cloned rootvg volume group and associated logical volumes.
Creating logical volume alt_hd5.
Creating logical volume alt_hd6.
Creating logical volume alt_hd8.
Creating logical volume alt_hd4.
Creating logical volume alt_hd2.
Creating logical volume alt_hd9var.
Creating logical volume alt_hd3.
Creating logical volume alt_hd1.
Creating logical volume alt_hd10opt.
Creating logical volume alt_hd11admin.
Creating logical volume alt_lg_dumplv.
Creating logical volume alt_livedump.
Creating /alt_inst/ file system.
Creating /alt_inst/admin file system.
Creating /alt_inst/home file system.
Creating /alt_inst/opt file system.
Creating /alt_inst/tmp file system.
Creating /alt_inst/usr file system.
Creating /alt_inst/var file system.
Creating /alt_inst/var/adm/ras/livedump file system.
Restoring mksysb image to alternate disk(s).
Linking to 64bit kernel.
Changing logical volume names in volume group descriptor area.
Fixing LV control blocks...
forced unmount of /alt_inst/var/adm/ras/livedump
forced unmount of /alt_inst/var/adm/ras/livedump
forced unmount of /alt_inst/var
forced unmount of /alt_inst/var
forced unmount of /alt_inst/usr
forced unmount of /alt_inst/usr
forced unmount of /alt_inst/tmp
forced unmount of /alt_inst/tmp
forced unmount of /alt_inst/opt
forced unmount of /alt_inst/opt
forced unmount of /alt_inst/home
forced unmount of /alt_inst/home
forced unmount of /alt_inst/admin
forced unmount of /alt_inst/admin
forced unmount of /alt_inst
forced unmount of /alt_inst
Fixing file system superblocks...
Bootlist is set to the boot disk: hdisk1 blv=hd5
(0)[opslab172] /mksysb
Now we can boot from the migrated disk without any issues. 
 

Document Location

Worldwide

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Document Information

Modified date:
30 April 2024

UID

ibm17145578

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