lttng snapshot record fails if no "output" is set
If you were to do:
$ lttng create snaps --snapshot Session snaps created. Default snapshot output set to: /home/daniel/lttng-traces/snaps-20130729-143544 Snapshot mode set. Every channel enabled for that session will be set in overwrite mode and mmap output. $ lttng enable-channel ch0 --buffers-pid -u UST channel ch0 enabled for session snaps $ lttng enable-event -a -c ch0 -u All UST events are enabled in channel ch0 $ lttng start Tracing started for session snaps $ /usr/src/lttng-ust-2.3.0-rc1/doc/examples/easy-ust/sample sample starting sample done $ lttng snapshot del-output snapshot Snapshot output snapshot successfully deleted for session snaps $ lttng snapshot list-output Snapshot output list for session snaps None $ lttng snapshot record Snapshot recorded successfully for session snaps
But of course no actual snapshot is recorded to disc. You should really get an error if you try to
snapshot record while no "output" (output parameter set) is defined.