Check if log4j.appender.RFA is defined in $HBASE_CONF_DIR/log4j.properties
If not please add the same.
eg:from https://svn.apache.org/repos/asf/hbase/trunk/conf/log4j.properties
# Rolling File Appender properties
hbase.log.maxfilesize=256MB
hbase.log.maxbackupindex=20
# Rolling File Appender
log4j.appender.RFA=org.apache.log4j.RollingFileAppender
log4j.appender.RFA.File=${hbase.log.dir}/${hbase.log.file}
log4j.appender.RFA.MaxFileSize=${hbase.log.maxfilesize}
log4j.appender.RFA.MaxBackupIndex=${hbase.log.maxbackupindex}
log4j.appender.RFA.layout=org.apache.log4j.PatternLayout
log4j.appender.RFA.layout.ConversionPattern=%d{ISO8601} %-5p [%t] %c{2}: %m%n