Unable to boot off USB Drive

[Hans Petter Selasky]

On Thursday 15 July 2010 17:22:11 James Armstrong wrote:
> On Thu, Jul 15, 2010 at 08:17, Hans Petter Selasky <hselasky at c2i.net> wrote:
> > On Thursday 15 July 2010 15:49:37 James Armstrong wrote:
> > > We're trying to boot a machine off a USB drive, and it looks like we're
> > > getting a race condition.  After going through post, we get the message
> > > "FAILED TO MOUNT ROOT" and we enter the mountroot command screen, but
> > > amidst that screen, we also get the post message identifying the disk,
> > > with the notation that it has a 40.00000MB transfer speed.
> > > 
> > > At the mountroot prompt, entering "ufs:/dev/da0s1a" properly boots.
> > > 
> > > It looks to me like the system is trying to mount root before the USB
> > > drivers finish identifying all the devices, including the disk from
> > > which we are booting.
> > > 
> > > Have any of you seen this?  Any suggestions on how we can correct this?
> > > (As an interim, we're going to move the boot to a SATA drive, but we
> > > want to use all the SATA ports for other purposes, so this means we're
> > > sacrificing a SATA device.)
> > 
> > Try to set this tunable to 5000, for example.
> > 
> > kern.cam.boot_delay: 0
> 
> This was one of the first things we tried (set at 10000).  No joy.

How did you set this variable? It should work. Do you see a 10 second delay at 
boot before mountroot?

--HPS