Enabling kernal level debugging with rbd

I m facing some issue while doing dynamic debug with rbd kernel steps: 1. sudo cat /boot/config-`uname -r` | grep DYNAMIC_DEBUG CONFIG_DYNAMIC_DEBUG=y 2.sudo mount -t debugfs none /sys/kernel/debug 3.sudo echo 9 > /proc/sysrq-trigger 4.sudo echo 'module rbd +p' | sudo tee -a /sys/kernel/debug/dynamic_debug/control in the last step I am getting error `tee: /sys/kernel/debug/dynamic_debug/control: Invalid argument` Can anyone tell me how to resolve this? Thank You.