Fstrace is an AFS utility which logs a huge amount of information about the internal operations of the AFS cache manager. It can provide details of the process flow through the AFS cache manager, without requiring any recompilation or specific debug options.
To use fstrace, you need a /usr/vice/etc/C/afszcm.cat file to be installed. Unfortunately, this file is not currently installed as part of RPM builds, and without it, the output from fstrace is pretty much useless. However, you should be able to take the afszcm.cat file from any build of the same AFS version and use it with your kernel module.
To start logging, initialize the logging system with
- fstrace clear cm
- fstrace setlog cmfx -buffers 100
and then, to start the logging session, and dump the log output to a file
- fstrace sets cm -active
- fstrace dump -follow cmfx -file /tmp/log -sleep 10 &
Then, perform the operations which you want to obtain a log for. You may find that the dump needs a short period of time (or another command to be invoked) in order to flush all of the data from the command that you’re logging onto disk.
To stop logging, run
- fstrace sets cm -inactive
Update 27/03/09: As of OpenAFS 1.4.9, the afszcm.cat file will ship as part of the standard RPM installation