Mounting / using /dev/ufs/name

[Dylan Cochran]

On Wed, Jan 14, 2009 at 1:00 PM, Václav Haisman <v.haisman at sh.cvut.cz> wrote:
> Hi,
> I tried to mount root slice using the device nodes provided in /dev/ufs
> directory. It works fine for other slices but not for the root slice. If I
> try it I get prompt asking for root slice at boot time. It this not possible
> at all or am I doing something wrong?

You should add vfs.root.mountfrom="ufs:ufs/whatever" to /boot/loader.conf

This will short circuit the bootloader's attempts to resolve it from
the rootdev:/etc/fstab entry for /, which, occasionally, will be
unable to deal with an fstab with an otherwise legal ufs label. I
noticed it a few years ago when I moved every machine I had to using
geom_label to find the root device, but I was unable to find the
source of the bug in the code (src/sys/boot/common/boot.c, the
getrootmount routine).