Switching Between 32 and 64 Bit AIX 5 Kernels

Audience: System Administrators

Date: September 12, 2002

Switching From 32 to 64 Bit Mode

To switch from 32-bit mode to 64-bit mode run the following commands, in the given order:

1. ln -sf /usr/lib/boot/unix_64 /unix
2. ln -sf /usr/lib/boot/unix_64 /usr/lib/boot/unix
3. bosboot -ad /dev/ipldevice
4. shutdown -Fr
5. bootinfo -K (should now show 64)

Switching From 64 To 32-Bit Mode

To switch from 64-bit mode to 32-bit mode run the following commands, in the given order:

1. ln -sf /usr/lib/boot/unix_mp /unix
2. ln -sf /usr/lib/boot/unix_mp /usr/lib/boot/unix
3. bosboot -ad /dev/ipldevice
4. shutdown -Fr
5. bootinfo -K (should now show 32)