Issue with innobackupex /path/to/backup

When innobackupex starts copying database folders getting: [Warning] Too many connections;
Could you please advice ?

To me it look likes you are using MyISAM engine for most of the tables and tables gets locked during the copy process and it yields “Too many connections”. Can you please confirm ? mysql processlist gives you clear idea what actually causing this issue either bad queries running too long or queries gets locked. What is your current setting of max_connections and does log_warnings is enabled ?