Try this:
1.# mwa stop all
Wait for all processes to terminate.
2.#ttd -k
3. Move the log files (/var/opt/perf/data/logxxx) into a different directory for later access or remove it.
4. Restart mwa to create the new logfile set
#mwa start all

NB:
What is wma?
mwa – performance tool script for starting and stopping data collection and alarms
mwa is a script  that  is  used  to  start,  stop,  and  re-initialize  HP Performance Agent processes.
On Sun Solaris,IBM/AIX and Tru64 UNIX systems, depending on which  communication  protocol  is installed and running, you can
choose a protocol selector (ncs or dce).