I have a MySQL server with binary logging active. Once a days logs file is "rotated", i.e. MySQL seems to stop writing to it and creates and new log file. For example, I currently have these files in /var/lib/mysql

-rw-rw---- 1 mysql mysql 10485760 Jun  7 09:26 ibdata1
-rw-rw---- 1 mysql mysql  5242880 Jun  7 09:26 ib_logfile0
-rw-rw---- 1 mysql mysql  5242880 Jun  2 15:20 ib_logfile1
-rw-rw---- 1 mysql mysql  1916844 Jun  6 09:20 mybinlog.000004
-rw-rw---- 1 mysql mysql 61112500 Jun  7 09:26 mybinlog.000005
-rw-rw---- 1 mysql mysql 15609789 Jun  7 13:57 mybinlog.000006
-rw-rw---- 1 mysql mysql       54 Jun  7 09:26 mybinlog.index

and mybinlog.000006 is growing.

Can I simply take mybinlog.000004 and mybinlog.000005, zip them up and transfer to another server, or I need to do something else before?

What info is stored in mybinlog.index? Only the info about the latest binary log?

UPDATE: I understand I can delete the logs with PURGE BINARY LOGS which updates mybinlog.index file. However, I need to transfer logs to another computer before deleting them (I test if backup is valid on another machine). To reduce the transfer size, I wish to bzip2 the files. What will PURGE BINARY LOGS do if log files are not "there" anymore?