环境：VMware Workstation centos7
主数据库配置：
server-id = 1
log_bin = /var/lib/mysql/binlog
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
从数据库配置：
server-id = 2
#relay_log = /home/mysql/sql_log/mysqld-relay-bin
log_bin = /var/lib/mysql/binlog

datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

从服务器可以ping同主服务器。从数据库启动slave是显示以下错误:
Last_IO_Errno: 2061
Last_IO_Error: error connecting to master ‘repl@192.168.81.139:3306’ - retry-time: 60 retries: 1

请问老师这个问题的原因是什么哈？