From: Shinobu Kinjo Date: Sat, 25 Nov 2017 01:22:00 +0000 (-0500) Subject: doc/dev/kernel-client-troubleshooting: Add kernel dynamic debuggin X-Git-Tag: v14.1.0~1034^2 X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=37046600f2234c87b85d232c479aca7c833facf8;p=ceph.git doc/dev/kernel-client-troubleshooting: Add kernel dynamic debuggin Signed-off-by: Shinobu Kinjo --- diff --git a/doc/dev/kernel-client-troubleshooting.rst b/doc/dev/kernel-client-troubleshooting.rst index 59e476148e5b..b6f7eff7beff 100644 --- a/doc/dev/kernel-client-troubleshooting.rst +++ b/doc/dev/kernel-client-troubleshooting.rst @@ -7,11 +7,15 @@ figuring out whether the problem is with the client or the MDS. Generally, this is easy to work out. If the kernel client broke directly, there will be output in dmesg. Collect it and any appropriate kernel state. If the problem is with the MDS, there will be hung requests that the client -is waiting on. Look in ``/sys/kernel/debug/ceph/*/`` and cat the ``mdsc`` file to -get a listing of requests in progress. If one of them remains there, the +is waiting on. Look in ``/sys/kernel/debug/ceph/*/`` and cat the ``mdsc`` file to get a listing of requests in progress. If one of them remains there, the MDS has probably "forgotten" it. We can get hints about what's going on by dumping the MDS cache: ceph mds tell 0 dumpcache /tmp/dump.txt And if high logging levels are set on the MDS, that will almost certainly hold the information we need to diagnose and solve the issue. + +You can also enable dynamic debug against the cephfs module. + +See: +https://github.com/ceph/ceph/blob/master/src/script/kcon_all.sh