The Zones Parallel Patching feature is now available in the latest Solaris 10 patch utilities patch, 119254-66 (SPARC) and 119255-66 (x86).

This is available for use on all Solaris 10 systems.

Simply install this patch, set the maximum number of non-global zones to be patched in parallel in the config file /etc/patch/pdo.conf, and away you go.

Prior to this feature, each non-global zone was patched sequentially, leading to unnecessarily long patching times for zones systems.  (Sequential patching remains the default behavior unless the config file is edited to enable Zones Parallel Patching.)

With this feature invoked, the global zone continues to be patched first, but then the non-global zones can be patched in parallel, leading to significant performance gains in patching operations on Zones systems.

While the performance gain is dependent on a number of factors, including the number of non-global zones, the number of on-line CPUs, the speed of the system, the I/O configuration of the system, etc., a performance gain of ca. 300% can typically be expected for patching the non-global zones – e.g. On a T2000 with 5 sparse root non-global zones.

More info at: http://blogs.sun.com/patch/entry/zones_parallel_patching_feature_now