Hi ,
i wrote a new rule for detecting a USB drive(thump drive) connected and automatically create a file in USB drive connected. The rule which i wrote is given below.

KERNEL="sd[a-z][0-9]",SYMLINK="My_USB",RUN+="/usr/bin/script.sh"

when i connected the USB drive, the symbolic name got created . but the script is not getting executed.

The script i wrote is as follows.

#!/bin/sh
echo "Hii"
mount /dev/My_USB usb
cd usb
touch ff.txt
cd ..
umount /dev/My_USB


Why 'RUN+' command is not working...? is there any problem in my script file? If i am running this script seperately it's working fine.

I am using RED HAT enterprise edition 4 and kernal version 2.6.20.14

Please help...

Are there SerialATA or SCSI hard drives in your box?
It could be the reason, because My_USB became a link to the HDD already.

i have SCSI hard disk in my system .. I am able to create the symbolic name My_USB and if i am running the script seperately, i am able to perform the operation using the same symbolic link. That means link is created properly right? Only when i am trying to invoke the script through RUN+=RUN+="/usr/bin/script.sh", the required action is not taking place.

How do you know your script isn't being executed? You are not recording any information in a meaningful way (stdout is redirected to /dev/null). Try touching a file in '/tmp' or something to give you an indication of what's happening.

when i am running the script seperately after creating a symbolic link for USB drive, the required file is getting created in the USB drive(thump drive). But if i am trying to execute the script using the RUN+= option in the UDEV rule, the file is not getting created in the USB drive. from this i concluded that the script is not getting executed if i am tring with UDEV RUN+= option.

As Vit77 already wrote, udev doesn't like double links. I'd suggest to try the script from the udev rule without the "mount" and "umount" commands.