The process of shutting down a Solaris system is critical. Using the init program to restart a system causes Solaris to perform a sequence of steps to shutdown services gracefully.
The reboot command bypasses the runtime control scripts and can compromise data integrity. The sync commands synchronize the filesystem, flushing buffered data to disk.
sync; sync; init 6
If this does not work on your version of Solaris, the comments from our helpful users below will get you going in the correct direction.