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.
On Wed, Jun 24, 2020 at 9:37 PM Abhinav Singh <singhabhinav0796@gmail.com> wrote:
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
This step is not strictly necessary, but since you've listed it, you need to use "sudo tee" here as well. Otherwise this command would fail with "Permission denied" because the shell would process the redirect to /proc/sysrq-trigger before running "sudo echo 9".
4.sudo echo 'module rbd +p' | sudo tee -a /sys/kernel/debug/dynamic_debug/control
Use "sudo tee" instead of "sudo tee -a", i.e. don't try to append instead of overwriting. sudo before echo is bogus for the reason mentioned above. To summarize, you need: $ echo 9 | sudo tee /proc/sysrq-trigger $ echo 'module rbd +p' | sudo tee /sys/kernel/debug/dynamic_debug/control Thanks, Ilya
participants (2)
-
Abhinav Singh
-
Ilya Dryomov