shutdown or reboot

init stateFunction
0Firmware Open Boot
S or sSingle User Mode
1Admin
2Multiuser, no NFS
3Multiuser with NFS
4Usually Unused
5Shutdown
6Reboot

Put the system into init5 state for poweroff
shutdown -y -i5 -g0
Put it into init6 for reboot
shutdown -y -i6 -g0

Secure disk wiping

This uses the purge utility built into the format command. Boot the system off a cd to single user mode with boot cdrom -s
Type format and select the analyse menu, select purge and slice 2 for the whole disk. The program warns you that it eill take a considerable amount of time, it's not kidding. This could take several hours or more depending on the disk size.
Sun Tech FAQ
This is supposed to " overwrite the available disk sectors with patterns that comply with the Department of Defense declassification regulations for data remanence. ".

Start system without X

bash-3.00# /usr/dt/bin/dtconfig -d
done
desktop auto-start disabled.

Install patch Cluster

Patch needs to be done in Single user mode:
# init S
Copy device names to backup in case they are overwritten, and do install
# cp /kernel/drv/sd.conf /kernel/drv/sd.conf.pre_cluster_installation
# cp /kernel/drv/st.conf /kernel/drv/st.conf.pre_cluster_installation

# cd $PATCH_CLUSTER_DIRECTORY
# ./install_cluster
Errors:-
Installation of patch failed. Return code 2.
Installation of patch failed. Return code 8.
Code 2 means patch already installed.
Code 8 means that the patch is for a package not present on the system.
Copy device descriptions back if needed (check files with diff) & reboot system
# mv /kernel/drv/sd.conf.pre_cluster_installation /kernel/drv/sd.conf
# mv /kernel/drv/st.conf.pre_cluster_installation /kernel/drv/st.conf

# shutdown -i6 -g0 -y
Use showrev & showrev -p to show version of Solaris and the patches installed.

Reconfiguration boot

touch /reconfigure