file system trace clearance in unix

-To clear old trace files and check the large files present in the file system
find . -name *.arc.Z -type f -atime +30 -exec rm {} \;
find . -name "OCMPROD_DB*" -atime +9 -exec rm -rf {} \;
find . -name "ora_audit*" -atime +60 -exec rm -rf {} \;

du -a . | sort -n -r | head -n 50

--To kill  multiple sessions
ps -ef | grep oracle | grep gzip |awk '{print "kill -9 ",$2;}' > /tmp/killparrt