Operating system update management

Abstract

Disclosed aspects relate to operating system update management for a shared pool of configurable computing resources having a plurality of logical partitions (LPARs). An operating system update request may be received. A set of original shared portions and a set of original individualized portions may be classified with respect to a set of original files on a set of original nodes. A set of original overlay links may be created for the set of original files. A set of operating system network traffic may be routed using the set of original overlay links. A set of successor files may be established on a set of surrogate nodes. A set of successor overlay links may be created for the set of successor files. The set of operating system network traffic may be routed using the set of successor overlay links in place of the set of original overlay links.

What is claimed is: 
     
         1 . A computer-implemented method of operating system update management for a shared pool of configurable computing resources having a plurality of logical partitions (LPARs), the method comprising:
 receiving an operating system update request for the shared pool of configurable computing resources;   classifying, with respect to a set of original files on a set of original nodes, a set of original shared portions and a set of original individualized portions, wherein a respective original file of the set of original files has a respective original shared portion and a respective original individualized portion,
 wherein the set of original shared portions includes a set of original base operating system images, 
 wherein the set of original individualized portions is selected from the group consisting of a set of original technology levels, and a set of original service packs; 
   creating, for the set of original files on the set of original nodes, a set of original overlay links including a respective original overlay link for the respective original file of the set of original files;   routing a set of operating system network traffic using the set of original overlay links;   establishing, to succeed the set of original files on the set of original nodes, a set of successor files on a set of surrogate nodes, wherein a first respective successor file of the set of successor files maps to a single successor shared storage segment and a first respective successor individualized storage segment, and wherein a second respective successor file of the set of successor files maps to the single successor shared storage segment and a second respective successor individualized storage segment,
 wherein the single successor shared storage segment includes a single successor base operating system image which is common for the plurality of LPARs, 
 wherein the first respective successor individualized storage segment includes a first successor technology level, and wherein the second respective successor individualized storage segment includes a second successor technology level which differs from the first successor technology level, 
 wherein the first respective successor individualized storage segment includes a first successor service pack, and wherein the second respective successor individualized storage segment includes a second successor service pack which differs from the first successor service pack; 
   creating, for the set of successor files on the set of surrogate nodes, a set of successor overlay links including: a successor shared overlay link which maps to the single successor shared storage segment, a first respective overlay link which maps to the first respective successor individualized storage segment, and a second respective overlay link which maps to the second respective successor individualized storage segment;   routing, in place of the set of original overlay links, the set of operating system network traffic using the set of successor overlay links;   performance of a live kernel update (LKU) operation;   incrementing, for each original overlay link of the set of original overlay links, an original overlay link usage count;   decrementing, for each original overlay link of the set of original overlay links switched to the set of successor overlay links, the original overlay link usage count;   detecting, in response to an LKU operation, that the original overlay link usage count has shrunk to zero;   removing, in response to detecting that the original overlay link usage count has shrunk to zero, the respective original shared portion of the respective original file of the set of original files;   invalidating the set of original overlay links;   validating the set of successor overlay links; and   freeing a chunk of storage corresponding to the set of original files.