Starting with AIX® Version 7.2, the AIX operating system provides the AIX Live Update function that eliminates the workload downtime that is associated with AIX system restart that is required by previous AIX releases when fixes to the AIX kernel are deployed. The workloads on the system are not stopped in a Live Update operation, yet the workloads can use the interim fixes after the Live Update operation.
IBM® delivers kernel fixes in the form of interim fixes to resolve issues that are reported by customers. If a fix changes the AIX kernel or loaded kernel extensions that cannot be unloaded, the host logical partition (LPAR) must be restarted. To address this issue, AIX Version 7.1, and earlier, provided concurrent update-enabled interim fixes that allow deployment of some limited kernel fixes to a running LPAR. All fixes cannot be delivered as concurrent update-enabled interim fixes. Starting with AIX Version 7.2, you can use the Live Update function to eliminate downtime that is associated with the AIX kernel update operation. This solution is not constrained by the same limitations as in the case of concurrent update enabled interim fixes.
AIX Version 7.2 Service Pack 1 contains significant fixes for AIX Live Update. You can download AIX Version 7.2 Service Pack 1 at the Fix Central website.
In AIX Version 7.2 with the 7200-01 Technology Level, or later, you can use the Live Update function to update service packs and technology levels for the AIX operating system.
In AIX Version 7.2 with the 7200-02 Technology Level, or later, partitions that are managed by IBM Power® Virtualization Center (PowerVC) can use the Live Update function.
You can watch an overview of the Live Update function here.