Users have been able to hotpatch since AIX 6.1, and in fact, IBM Support delivers concurrent update Interim fixes that allow kernel patches without a reboot. Still, in some situations, fixes could not be coded with this approach.
AIX Live Update now allows all interim fixes, service packs, and technology levels to be applied without the need to reboot by exploiting LPAR virtualization, AIX virtualization and alt-disk install technology. AIX Live Update can:
• Create a new LPAR with an updated running kernel
• Provide a live migration while running workloads to this new LPAR
• Clean up the original LPAR when complete
AIX 7.2 TL0 SP0 (interim fixes) / AIX 7.2 TL1 SP0 (service packs and technology levels)