What happens to the existing logs when changes are made to "NameNode Maximum Log File Backups"

[#1]

Because of space issues we have made changes to "NameNode Maximum Log File Backups" and reduced it from 10 to 5 . 

Are those extra log files deleted automatically ? or should i delete them manually 

-rw-r--r-- 1 hdfs hdfs 201M Jan 20 15:44 hadoop-cmf-hdfs-NAMENODE.log.out.10
-rw-r--r-- 1 hdfs hdfs 201M Jan 21 11:26 hadoop-cmf-hdfs-NAMENODE.log.out.9
-rw-r--r-- 1 hdfs hdfs 201M Jan 22 07:13 hadoop-cmf-hdfs-NAMENODE.log.out.8
-rw-r--r-- 1 hdfs hdfs 201M Jan 23 02:58 hadoop-cmf-hdfs-NAMENODE.log.out.7
-rw-r--r-- 1 hdfs hdfs 201M Jan 23 22:44 hadoop-cmf-hdfs-NAMENODE.log.out.6
-rw-r--r-- 1 hdfs hdfs 201M Jan 25 10:54 hadoop-cmf-hdfs-NAMENODE.log.out.5
-rw-r--r-- 1 hdfs hdfs 201M Jan 26 06:54 hadoop-cmf-hdfs-NAMENODE.log.out.4
-rw-r--r-- 1 hdfs hdfs 201M Jan 29 05:30 hadoop-cmf-hdfs-NAMENODE.log.out.3
-rw-r--r-- 1 hdfs hdfs 201M Feb 9 02:38 hadoop-cmf-hdfs-NAMENODE.log.out.2
-rw-r--r-- 1 hdfs hdfs 201M Feb 13 19:59 hadoop-cmf-hdfs-NAMENODE.log.out.1

[#2]

Hi

It depends on the retention period for log deletion, it will automatically get deleted after the specified time period or else If you want you can flush the logs manually.