AIX Switching Kernel Bit Modes

Switching to the 32 bit Kernel

1. # ln -sf /usr/lib/boot/unix_mp /unix
2. # ln -sf /usr/lib/boot/unix_mp /usr/lib/boot/unix
3. You will need to note which hdisks that hd5 appears on.
   1. # lslv -m hd5
4. Change the base operating system boot devices repeat for each disk listed in previous step.
   1. # bosboot -ad <hdisk#>
5. Add the drives to the bootlist that where listed with the lslv command.
   1. # bootlist -m normal <hdisk#> ... <hdisk#n>
6. Restart the server to apply the changes.
7. Verify that the server is running the 32 bit kernel.
   1. # bootinfo -K

Switching to the 64 bit Kernel

1. # ln -sf /usr/lib/boot/unix_64 /unix
2. # ln -sf /usr/lib/boot/unix_64 /usr/lib/boot/unix
3. You will need to note which hdisks that hd5 appears on.
   1. # lslv -m hd5
4. Change the base operating system boot devices repeat for each disk listed in previous step.
   1. # bosboot -ad <hdisk#>
5. Add the drives to the bootlist that where listed with the lslv command.
   1. # bootlist -m normal <hdisk#> ... <hdisk#n>
6. Restart the server to apply the changes.
7. Verify that the server is running the 64 bit kernel.
   1. # bootinfo -K

Resources

1. IBM pSeries and AIX Information Center
2. AIX Commands you should not leave home without