On Sun, 10 Jun 2007 19:30:16 +0200, Don Hayward wrote:
> I have a new Seagate FreeAgent usb hard drive. After install, it spins
> down and when one tries to write to it, it gets marked read only. This
> can be prevented by running the following command line:
>
> echo 1 > /sys/class/scsi_disk/14\:0\:0\:0/allow_restart
>
> where this bit^^^ varies with each connection.
>
> I'd like to get udev to set this for me, so I tried the following rule:
>
> SYSFS{model}=="FreeAgentDesktop",RUN+="/bin/echo 1 >
> /sys/class/scsi_disk/%k/allow_restart"
>
> It doesn't work. Allow_restart is always 0 after a connection.
>
> I've also tried:
> SYSFS{model}=="FreeAgentDesktop",RUN+="/bin/echo 1 >
> /sys/class/scsi_disk/%b/allow_restart"
> SYSFS{model}=="FreeAgentDesktop",RUN+="/bin/echo 1 >
> '/sys/class/scsi_disk/%k/allow_restart'"
> SYSFS{model}=="FreeAgentDesktop",RUN+="/bin/echo 1 >
> '/sys/class/scsi_disk/%b/allow_restart'"
>
> because I'm confused about 1) which string substitution holds the
> identifier I need, and 2) the need for quoting or escaping the ':' in
> the line.
>
> udevtest shows this:
> parse_file: reading '/etc/udev/rules.d/10-local.rules' as rules file and
> this
> main: run: 'socket:/org/freedesktop/hal/udev_event' so my rule seems to
> be picked up.
>
> udevinfo -a -p /sys/block/sdd
> shows:
>looking at parent device
>'/devices/pci:00/:00:06.0/:02:0b.2/usb5/5-3/5-3:1.0/
host14/target14:0:0/14:0:0:0':
> KERNELS=="14:0:0:0"
> ATTRS{model}=="FreeAgentDesktop"
> ...
>
> So my questions are:
> 1) what string substitution do I use to get the needed bit into my
> command? 2) do I need quoting in the rule?
> 3) can this work anyway?
>
> Thanks for any help.
>
> Don
>
I have found the rules easy to write and writing the executables called
tricky. This following is a kludge: with probably some over the top and
uneccessary parts. It is adapted from a udev triggered script I use to
get my scripts to run in xterminals - perhaps that will help your script
to work. And perhaps someone here can help clean it up.
First put your line in a script (I am assuming you need to run the
command as root - in which case you will need to set up sudo to work for
this...):
#!/bin/bash
sudo echo 1 > /sys/class/scsi_disk/14\:0\:0\:0/allow_restart
#Delete the following 2 lines once everything is working
echo 'udev executed script finished: Press enter.'
read ARG
The effect of the last two lines is to give you a chance to see any
relevant output for troubleshooting. Call the script, say,
scsiScriptForUdev. Test it, make it executable and save it in /usr/
bin/...
#!/bin/bash
if [ "$ACTION" != 'add' ] ; then
exit
fi
export PATH=/bin:/sbin:/usr/bin:/usr/sbin
LocalDisplay=':0'
X11User=`who | grep $LocalDisplay | sed -n 1p | cut -f 1 -d ' '`
Command='sudo xterm -e scsiScriptForUdev'
export DISPLAY=$LocalDisplay
nice -n 19 su $X11User -c "$Command &> /tmp/udevScriptErrorOutput.txt" &
Seems crazy and I am sure there is a neater way to do it - but perhaps
with the xterm output and the output in the /tmp/ text file you will have
more information to work with.
If you do manage to get it working and/or optimise it let us know.
Graham
