Snap traces are controlled by -Xdump. They contain the tracepoint data held in the trace buffers.
The example below shows the production of a snap trace.
java -Xgcpolicy:metronome -Xdump:snap:events=vmstop -version JVMDUMP006I Processing dump event "vmstop", detail "#00000000" - please wait. JVMDUMP007I JVM Requesting Snap dump using '/home/user/Snap.20090603.063646.315586.0001.trc' JVMDUMP010I Snap dump written to /home/user/Snap.20090603.063646.315586.0001.trc JVMDUMP013I Processed dump event "vmstop", detail "#00000000".
Snap traces require the use of the trace formatter for further analysis.
See Using the trace formatter for more information about analyzing a snap trace.