Managing Multiple Boot Environments

A boot environment, also called a BE, is a bootable instance of the Oracle Solaris operating system image, plus any other application software packages that are installed on that image. You can maintain multiple boot environments on a single system, and each boot environment can have a different software version installed.

Upon the initial installation of the operating system, a boot environment is created on your system. Use the Boot Environment Management tool or the beadm command to administer additional boot environments on your system.

Why Use Multiple Boot Environments?

With multiple boot environments, the process of updating software becomes a low risk operation because you are able to create backup boot environments before making any software updates to your system. If necessary, you have can boot a backup BE.

The ability to create different boot environments enables you to have different environments for different versions of tools that you use. Shared files are not affected by creating a new boot environment. If you modify files in a newer boot environment, and then boot to an older boot environment, the files are also modified for that boot environment. You cannot retrieve an older version of a shared file from an older boot environment.

You can maintain more than one boot environment on your system at the same time and perform various upgrades on each of them. For example, you can clone a boot environment by using the beadm create command. A clone is a bootable copy of a boot environment. Then, you can install, test, and update different software packages on the original boot environment and on its clone.

Although only one boot environment can be active at any given time, you can mount an inactive boot environment by using the beadm mount command. Then you can use the pkg update command to update all of the packages in that inactive, mounted environment that have available updates. Or, use the pkg install package-name command, with the -R option to update specific packages in that boot environment.

Managing Boot Environments by Using Package Manager

You can use Package Manager to manage your boot environments.

The following boot environment management tasks can be performed by using Package Manager:

• Display information about all of the boot environments on your installed system

• Delete old or unused boot environments

• Change the default boot environment on your system

• Activate a boot environment

How to Manage Boot Environments From the Desktop

1. Start Package Manager by choosing System -> Administration -> Package Manager, or by clicking the Package Manager icon that is located on the desktop.
2. Choose File-> Manage Boot Environments.

   The Boot Environment Management window opens, displaying all of the available boot environments that are on your installed system. Also displayed is the name of the operating system, the date the boot environment was created, and the size of the boot environment, in GB.

   • To delete a boot environment, click Delete, then click OK.
   • To change the default boot environment, place a check mark next to the new default boot environment, then click OK.
   • To activate a new boot environment, click Active on Reboot, then click OK.

     The new boot environment becomes active on the next system reboot.