Unable to boot off USB Drive

[Hans Petter Selasky]

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

--HPS