From 189426777484a0857327957ea47ec7a308700437 Mon Sep 17 00:00:00 2001 From: Zac Dover Date: Tue, 12 Aug 2025 16:46:12 +1000 Subject: [PATCH] doc/cephfs: edit troubleshooting.rst Edit the "Dynamic Debugging" section of doc/cephfs/troubleshooting.rst. Signed-off-by: Zac Dover doc/cephfs: improve dynamic debugging section Signed-off-by: Venky Shankar (cherry picked from commit a15653a2fbb385aae4cfa5245728b3e14e705bfe) --- doc/cephfs/troubleshooting.rst | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/doc/cephfs/troubleshooting.rst b/doc/cephfs/troubleshooting.rst index 8d47f4e4a68..609d4ab019f 100644 --- a/doc/cephfs/troubleshooting.rst +++ b/doc/cephfs/troubleshooting.rst @@ -375,9 +375,29 @@ and then reinstall it so that you have the latest version. Dynamic Debugging ================= -You can enable dynamic debug against the CephFS module. +Dynamic debugging for CephFS kernel driver allows to enable or disable debug +logging. The kernel driver logs are written to the kernel ring buffer and can +be examined using ``dmesg(1)`` utility. Debug logging is disabled by default +because enabling debug logging can result in system slowness and a drop in I/O +throughput. -Please see: https://github.com/ceph/ceph/blob/master/src/script/kcon_all.sh +Enable dynamic debug against the CephFS module. + +See: https://github.com/ceph/ceph/blob/master/src/script/kcon_all.sh + +Note: Running the above script enables debug logging for the CephFS kernel +driver, libceph, and the kernel RBD module. To enable debug logging for a +specific component (for example, for the CephFS kernel driver), run a command of the following form: + +.. prompt:: bash # + + echo 'module ceph +p' > /sys/kernel/debug/dynamic_debug/control + +To disable debug logging, run a command of the following form: + +.. prompt:: bash # + + echo 'module ceph -p' > /sys/kernel/debug/dynamic_debug/control In-memory Log Dump ================== -- 2.39.5