welcome to the forum swapna_d
log4j.appender.D.DatePattern='.'yyyy-MM-dd-HH-mm
causes the log file to be rolled over every minute. Can you try removing
HH-mm, I think that should fix the problem.
But if it's not copying your log file every minute than problem might be something else, please write back if this is the case.
DailyRollingFileAppender (Apache Log4j 1.2.15 API)