Hi All, I'm trying to disable USB storage devices in Centos7.1.1503. I've setup udev rules to block all usb devices and then additional rules to allow specific vendors / products to be used (mainly keyboards and mice). This is all working perfectly. cat /etc/udev/rules.d/01-usblockdown.rules # Block all USB devices ACTION=="add", SUBSYSTEMS=="usb", RUN+="/bin/sh -c 'for host in /sys/bus/usb/devices/usb*; do echo 0 > $host/authorized_default; done'" # Allow devices # Keyboards ACTION=="add", ATTR{idVendor}=="04f3", ATTR{idProduct}=="0103" RUN+="/bin/sh -c 'echo 1 >/sys$DEVPATH/authorized'" ...... Now I'm testing against mobile devices and when I connect an Asus mobile telephone it's mounting the camera using PTP even though the device is not allowed in my udev rules. I removed libgphoto2 which has now stopped the PTP from automounting. My issue is that I require hplip on my systems for certain printer drivers and this package was removed along with libgphoto2. I added an 'exclude=libgphoto2*' to my /etc/yum.repos.d/CentOS-Base.repo and installing hplip now fails on dependencies. Is there a method of disable libgphoto2 PTP without having to remove the package? or can I create further udev rules to stop PTP mounts? thanks in advance, Michael