by Antoine - Categories : OS
Boot Environments (BE) are like a system snapshot containing root data, including the OS. In ZFS language, they are like a system pool clone.
The goal of a BE is to create a system backup before the user makes any change on/update it. By the way, updating OpenSolaris with
pkg image-update command actually creates a new BE containing the system latest version. The olds system BE is not altered in the process so the administrator is able to easily rollback if the update happens to break something.
BE are controlled through the
Here is a quick overview of the most basic ones.
List active BE
# beadm list BE Active Mountpoint Space Policy Created -- ------ ---------- ----- ------ ------- opensolaris N / 2.58G static 2009-05-01 11:35 opensolaris-1 R - 61.0K static 2009-05-01 13:25
N (NOW) flag refers to the currently used BE, and
R (REBOOT) to the BE that will be used at next startup.
Activate and rename a BE
In order to rename a BE, some conditions must be met : not being N or R. If active, which is the case if the user just updated the system by
pkg image-update, another BE needs to be activated, renamed, and activated for the next startup.
# beadm activate opensolaris # beadm rename opensolaris-1 osol # beadm activate osol # beadm list BE Active Mountpoint Space Policy Created -- ------ ---------- ----- ------ ------- opensolaris N / 2.58G static 2009-05-01 11:35 osol R - 61.0K static 2009-05-01 13:25
Create and delete a BE
Easy again with
# beadm create opensolaris # beadm destroy opensolaris
For more commands and détails about above commands, see the SUN documentation.