Quick tip to collect Kernel RBD logs.

Make sure your kernel is compiled with CONFIG_DYNAMIC_DEBUG (and CONFIG_DEBUG_FS) enabled:

bash $ sudo cat /boot/config-`uname -r` | grep DYNAMIC_DEBUG CONFIG_DYNAMIC_DEBUG=y

Then mount debugfs:

bash $ sudo mount -t debugfs none /sys/kernel/debug

Set the console log level to 9:

bash $ sudo echo 9 > /proc/sysrq-trigger

Then chose the module that you want to log:

bash $ sudo echo 'module rbd +p' | sudo tee -a /sys/kernel/debug/dynamic_debug/control

Looking at dmesg will show the corresponding logs. You can use this script from the Ceph repo as well to enable all of them:

```bash

!/bin/sh -x

p() { echo "$*" > /sys/kernel/debug/dynamic_debug/control }

echo 9 > /proc/sysrq-trigger p 'module ceph +p' p 'module libceph +p' p 'module rbd +p' ```