Solaris 10 5/09 Installation Guide: Planning for Installation and Upgrade

Backing Up And Restarting Systems For an Upgrade

Backing up your existing file systems before you upgrade to the Solaris OS is highly recommended. If you copy file systems to removable media, such as tape, you can safeguard against data loss, damage, or corruption.

In previous releases, the restart mechanism enabled you to continue an upgrade after a loss of power or other similar problem. Starting with the Solaris 10 10/08 release, the restart mechanism is unreliable. If you have a problem, your upgrade might not restart.