To install or upgrade the Oracle Solaris OS, you need to boot from either CD/DVD, or from the network. In both instances, the miniroot's root file system is the ramdisk. This process enables you to eject the Solaris boot CD or DVD without having to reboot the system. Note that the boot archive contains the entire miniroot. The construction of the installation DVD has been modified to use an HSFS boot block. The miniroot is then packed into a single UFS file that is loaded as the ramdisk. Note that the miniroot is used for all OS installation types.