Use
the following commands to remove boot environments.
root@sup46:~# beadm list
BE Active Mountpoint Space Policy Created
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solaris_backup - - 13.25G static 2011-07-17 21:19
solaris NR - 4.12G static 2011-07-13 12:01
root@sup46:~# beadm destroy solaris_backup
Are you sure you want to destroy solaris_backup? This action cannot be undone(y/[n]): y
root@sup46:~# beadm list
BE Active Mountpoint Space Policy Created
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solaris NR / 4.12G static 2011-07-13 12:01
root@sup46:~#