[Nut-upsuser] USB problem as user

Peter Selinger selinger at mathstat.dal.ca
Sun Apr 22 00:56:53 UTC 2007


In this case, I recommend that you do some testing and figure out
yourself what the problem is. 

The debug output that you sent indicates that newhidups was unable to
find the USB device, not that it was unable to open it. So perhaps
this is not a permissions problem after all. Perhaps the device got
unplugged or unloaded. 

Do you see the device with "lsusb" or "usbview"? Do you see it with
"ls -lr /proc/bus/usb"?

Try alternating "-u root" and "-u nut" several times to make sure one
always works and the other one doesn't.

Also check that no other copy of newhidups is already running; you
can't attach two driver instances to a single device. 

Finally, to state the obvious: if your computer is a production system
that cannot be experimented with, then attach the UPS to another,
non-production system, and make sure it works there first. 

Good luck! -- Peter

Czuczy Gergely wrote:
> 
> On Fri, 20 Apr 2007 14:36:06 -0300 (ADT)
> selinger at mathstat.dal.ca (Peter Selinger) wrote:
> 
> > There are two solutions, and you almost mentioned them yourself.
> >
> > (1) run the driver and upsd with -u root, or
> This is the situation that I'd like to prevent.
> >
> > (2) change the permissions for the USB device corresponding to your
> >     UPS, which is most likely /proc/bus/usb/XXX/YYY, for certain
> >     values of XXX and YYY.
> As I have already told it, I've done this, but it does not work.
> Chown/modding the /proc/bus/usb to nut:nut (the user:group which
> the daemon runs with) recursively (that means, every dir and every
> sub-dir and file of it, and ever subdir of every subdir, so on...)
> seems not to be enough, since newhidups is unable to find the device,
> as I have pasted it previously.
> 
> >
> > If you do not have hotplugging or udev, then you cannot automate step
> > (2).
> >
> > -- Peter
> >
> > Czuczy Gergely wrote:
> > >
> > > Hello
> > >
> > > I'm having a bit of a trouble to set up a Back-UPS on
> > > a production box.
> > > We're using the newhidups driver for this module here, in
> > > the office, and I'd like to monitor the one, out in our
> > > server farm.
> > >
> > > The situation is the following:
> > > # /lib/nut/newhidups -u root -DD -a ups1 2> ups1.out
> > > Network UPS Tools: 0.28 USB communication driver 0.28 - core 0.30
> > > (2.0.5)
> > >
> > > this one worked flawlessly, while as a user, it cannot access
> > > the UPS:
> > >
> > > # /lib/nut/newhidups -u nut -DD -a ups1
> > > Network UPS Tools: 0.28 USB communication driver 0.28 - core 0.30
> > > (2.0.5)
> > >
> > > debug level is '2'
> > > No appropriate HID device found
> > > No matching HID UPS found
> > >
> > > I've chowned to nut:nut /dev/usb/* and /proc/bus/usb recursively,
> > > but it didn't help.
> > >
> > > I'd like to ask for help, what do i need to adjust on the system
> > > to make it work.
> > >
> > > Some circumstances:
> > > This is a production box. The kernel cannot be changed,
> > > it cannot be restarted, and it should be held in awe and
> > > respect. So I can only touch it as minimally as it's
> > > required.
> > >
> > > hotplug is not available here, so replugging is USB cable is
> > > out of question.
> > >
> > > # /etc/init.d/hotplug restart
> > >  * Kernel hotplug support not enabled.
> > >
> > > So, what should I do to make this work?
> > >
> > > --
> > > =C3=9Cdv=C3=B6zlettel,
> > >
> > > Czuczy Gergely
> > > Publishing Factory Kft
> > > http://www.publishing.hu/
> 




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