man 8 daily
etc/daily
     This script is run daily.  It currently does the following:
...
Creates a backup root file system which is updated daily.  This only
         happens if the following conditions are met:

               1.   The environment variable ROOTBACKUP must be set.  For ex-
                    ample, the following can be added to root's crontab(5):

                          ROOTBACKUP=1

               2.   The mount directory /altroot must exist, and there must be
                    an /etc/fstab entry specifying `xx' for the mount options,
                    e.g.

                          /dev/wd0j /altroot ffs xx 0 0
...
Thanks,
Josh


On 11/6/07, Frans Haarman <franshaarman@gmail.com> wrote:
quoted text
> Just wondering.......
>
> Has anyone ever thought of having 2 openbsd installations to boot from ?
> This way I could upgrade the installation on one slice/disk and boot from it!
>
> Then if the kernel would crash/reboot the other slice would be used for booting.
>
> So at boot time the active slice is changed, after booting its changed back
> if there are no troubles!
>
>
> Perhaps this is an ugly work around to most, but it might save my life when a
> system refuses to boot the active slice...... Most of this can be
> prevented with
> remote consoles or ILO stuff I guess!   What do you think ? FUD ? ;)