USB problem - how to disable an umass device?

Oliver Fromme olli at
Wed Mar 7 13:09:41 UTC 2007

Ivan Voras wrote:
 > I'm trying to install 6.2-release on an IBM blade center blade (AMD
 > Opteron), but the boot process hangs while accessing an embedded USB
 > storage device umass1. Since I don't think I'll ever need it, and I need
 > the blade, is there any way to disable probing or usage of umass1? I
 > think the problems arrive when FreeBSD tries to attach "da" device to it.

I'm afraid the only way is to compile a custom kernel that
does not have "device umass".  You might also have to make
sure there's no umass.ko in /boot/kernel (I'm not sure, but
it's possible that some mechanism like devd tries to load
umass.ko automatically).

Of course, a better way to solve the problem would be to
find out _why_ it is hanging in the first place.  :-)
The first step would be to enter the kernel debugger and
take a stack trace, in order to find out where it is stuck.

It might be a good idea to take this issue to the freebsd-
usb mailing list.

 > I tried using loader hint hint.usb.2.disabled="1" but it doesn't work.

Unfortunately, hints cannot be used to disable devices in
general (which would be a desirable feature).  That only
works for legacy devices (i.e. ISA) and some others.

Best regards

Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M.
Handelsregister: Registergericht Muenchen, HRA 74606,  Geschäftsfuehrung:
secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün-
chen, HRB 125758,  Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart

FreeBSD-Dienstleistungen, -Produkte und mehr:

(On the statement print "42 monkeys" + "1 snake":)  By the way,
both perl and Python get this wrong.  Perl gives 43 and Python
gives "42 monkeys1 snake", when the answer is clearly "41 monkeys
and 1 fat snake".        -- Jim Fulton

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