Lustre 1.6 Operations Manual

debug_daemon stop
Completely shuts down the debug_daemon operation and flushes the file output.
Otherwise, debug_daemon is shut down as part of Lustre file system shutdown
process. Users can restart debug_daemon by using start command after each stop
command issued.
This is an example using debug_daemon with the interactive mode of lctl to dump
debug logs to a 10 MB file.
#~/utils/lctl
To start daemon to dump debug_buffer into a 40 MB /tmp/dump file.
lctl > debug_daemon start /trace/log 40
To completely shut down the daemon.
lctl > debug_daemon stop
To start another daemon with an unlimited file size.
lctl > debug_daemon start /tmp/unlimited
The text message *** End of debug_daemon trace log *** appears at the
end of each output file.
23.2.2 Controlling the Kernel Debug Log
Masks in /proc/sys/portals/subsystem_debug and
/proc/sys/portals/debug controls the amount of information printed to the
kernel debug logs. The subsystem_debug mask controls the subsystems (example:
obdfilter, net, portals, OSC, etc.) and the debug mask controls the debug types
written out to the log (example: info, error, trace, alloc, etc.).
To turn off Lustre debugging:
sysctl -w lnet.debug=0
To turn on full Lustre debugging:
sysctl -w lnet.debug=-1
To turn on logging of messages related to network communications:
sysctl -w lnet.debug=net
To turn on logging of messages related to network communications and existing
debug flags:
sysctl -w lnet.debug=+net
23-6 Lustre 1.6 Operations Manual • September 2008