Single-user mode patch application
You must bring computers into single-user mode to prepare them for kernel-level or cluster-level patching.
By default, the BigFix Solaris Patch solution applies Solaris patches in the current run level of the computer. Typically, Solaris computers use Run Level 3 or Multi-User mode. In some cases, single-user mode is used to successfully apply the Solaris patch.
The Patches for Solaris and Patches for Solaris Maintenance sites provide a task to bring a Solaris system down to single-user mode called Single-User Mode Task - Solaris task (ID #28).
Note: Systems in single-user mode have extremely limited functionality
and restricted network connectivity. Users who are remotely connected
to the computer when the single-user mode action is applied lose their
connection. Do not put a system into single-user mode unless you understand
the effects of this action.