Tracing generates a trace log called log.trace, that is stored
in /usr/tank/server/log. Like other log files, this file has a maximum file
size of 250 MB. When it reaches this size, the SAN File System creates a
copy called log.trace.old and clears log.trace. If log.trace.old already
exists, it is overwritten.
Note: A minimum level of tracing always occurs
for the metadata server, so this file always exists.