I've been migrating some old systems from truly antique Sun boxes onto a small number of new Sun T5240s. Lots of zones, one per new physical system.
This includes some truly antique versions of oracle.
In order to keep the version police happy with the compatibility matrix, they wanted Solaris 8. Despite the fact that it works fine with Solaris 10, they insisted on Solaris 8. Enter Solaris 8 Containers.
Now, Solaris 10 has reasonable default shared memory settings. However, the Solaris 8 Container gives a faithful emulation of a Solaris 8 system, including miserly shared memory settings. How to set better values, because the normal Solaris 10 games don't apply?
The solution is simple, so simple that it never actually occurred to me. Simply put the settings you want in the Container's /etc/system file in the traditional way, and reboot the Container.