This SunSolve article describes the process for using Solaris Live Upgrade to upgrade from Solaris 8 to Solaris 10 05/08 or later releases.
The Solaris 10 05/08 release media (and subsequent updates) were compressed using a different compression utility than previous Solaris 10 releases, which all used bzip2 compression. As a result of this, in order to upgrade to Solaris 05/08 (or later releases) using Solaris Live Upgrade, the live system (on which
luupgrade is running), must have p7zip installed. p7zip was backported to the Solaris 9 OS in patch format, but for Solaris 8 there is no similar patch available. (For more info on patching, see the BigAdmin Patching hub.)