[NanoBSD] Can't use boot0cfg for changing the booting slice

[M. Warner Losh]

In message: <19068.18919.843159.936827 at gromit.timing.com>
            John Hein <jhein at timing.com> writes:
: Olivier Cochard-Labbé wrote at 17:09 +0200 on Aug  7, 2009:
:  > I meet a problem under FreeBSD 7.2 and 8.0-current (nanoBSD) using
:  > boot0cfg: I can't use boot0cfg for changing the booting slice.
:  > Here is my problem:
:  > I'm using the FreeBSD Boot manager on a system with MBR partitions.
:  > The active slice is the partition 1, but I want to boot from the slice 2.
:  > 
:  > Then I use boot0cfg like that:
:  > 
:  > sysctl kern.geom.debugflags=16
:  > boot0cfg -s 2 -v /dev/ad0
:  > sysctl kern.geom.debugflags=0
:  > 
:  > But, after the reboot my system still reboot from the slice 1 (but the
:  > boot loader show correctly that the default choice is now the 2)!
:  > Where is my problem ?
: 
: Are you sure you're booting from slice 1?
: Is fstab on slice 2 pointing to slice 1?

Also, boot0cfg won't mark the slice as ACTIVE, just remember that was
the last slice you booted from...  To mark it active, you must use
fdisk.  If by 'active' you mean 'what mount reports root as' then I
think John's suggestion is right on the money...

Warner