"scsi bus continuously busy"

Phil Blundell pb at pbcl.net
Sat May 2 15:00:54 CDT 2020

On Sat, May 02, 2020 at 10:22:02AM -0700, Alan Perry via cctalk wrote:
> >sc0 at vme24d16 200000 vec 0x40
> >sd0 at sc0 slave 0
> >si0:  sc_cmd:  scsi bus continuously busy
> >sc0:  resetting scsi bus
> >sd1 at sc0 slave 1

Not that I know these particular devices, but is it at all possible one
of the cables is in backwards?  That sounds like the kind of behaviour
you get with 50-pin SCSI if an IDC connector is upside down.

But otherwise, this message presumably means the host controller is
sensing BSY# asserted when it didn't expect it.  So the first order of
business would be to find out whether BSY# on the bus is genuinely
low.  If not, it must be a controller fault.  If yes, disconnect the
devices one at a time and see if the problem goes away.  If it's still
stuck low with no devices attached, the issue is either in the
controller or termination.


More information about the cctech mailing list