tying down adaX to physical interfaces

Kostik Belousov kostikbel at gmail.com
Sat Mar 26 13:52:20 UTC 2011


On Sun, Mar 27, 2011 at 12:24:03AM +1100, Bruce Evans wrote:
> On Sat, 26 Mar 2011, Kostik Belousov wrote:
> 
> >On Fri, Mar 25, 2011 at 05:21:50PM -0700, Michael DeMan wrote:
> >>Hi All,
> >>
> >>I seem to recall that there is a way to do this, but can no longer google 
> >>it.
> >>
> >>Basically, for NCQ support with SATA devices we are using the 'ada' 
> >>driver, which of course has SCSI like behavior.
> >>...
> >I use the following stanza in /boot/device.hints for machine with intel
> >on-board ahci and siis in pcie:
> >hint.scbus.0.at="ahcich0"
> >hint.ada.0.at="scbus0"
> >hint.scbus.1.at="ahcich1"
> >hint.ada.1.at="scbus1"
> >hint.scbus.2.at="ahcich2"
> >hint.ada.2.at="scbus2"
> >hint.scbus.3.at="ahcich3"
> >hint.ada.3.at="scbus3"
> >hint.scbus.4.at="ahcich4"
> >hint.ada.4.at="scbus4"
> >hint.scbus.5.at="siisch0"
> >hint.ada.5.at="scbus5"
> >hint.scbus.6.at="siisch1"
> >hint.ada.6.at="scbus6"
> 
> To hijack this thread a little, I'll ask how people handle removable media
> changing the addresses of non-removable media.  I use the following to
> prevent USB drives stealing da0 from my 1 real SCSI disk on 1 machine:
> 
>    hint.scbus.0.at="sym0"
>    hint.da.0.at="scbus0"
> 
> This works OK and is easy to manage with only 1 SCSI disk.  But 1 of my
> USB drives also steals cd0 from a not-so-real ATAPI drive under atapicam,
> depending on whether the USB drive is present at boot time:
> 
>    USB drive not present at boot time:
>      ad* (no SCSI disks on this machine)
>      cd0 = acd0 (but no further ATAPI drives on this machine)
>    insert USB drive:
>      da1 (da0 was reserved by above)
>      cd1 (phantom ATAPI drive on the USB drive.  Accessing this hangs
> 	  parts of the ata system but it doesn't get used since various
> 	  places only point cd0)
> 
>    USB drive present at boot time:
>      ad*
>      da1 on USB
>      cd0 phantom on USB
>      cd1 = acd[0 or 1] (normal cd0).  Accessing cd0 now hangs parts of the
> 	   ata system and this happens too easily since various places point
> 	   to cd0.
> 
> How do people defend agains random USB drives present or not at boot time?

Wouldn't it be cd0 on scbusX on ahciY, and cd1 on scbusZ on umass-simT ?
I believe similar hints would wire the cd0/cd1 in your case.
> 
> Bruce
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