磁盘写满导致MySQL复制失败的解决方案

案例场景
      今天在线上发现一个问题，由于监控没有覆盖到，某台机器的磁盘被写满了，导致线上MySQL主从复制出现问题。问题如下：
 localhost.(none)>show slave status\G*************************** 1. row ***************************               Slave_IO_State:                  Master_Host: 10.xx.xx.xx                  Master_User: replica                  Master_Port: 5511                Connect_Retry: 60              Master_Log_File:          Read_Master_Log_Pos: 4               Relay_Log_File: relay-bin.001605                Relay_Log_Pos: 9489761        Relay_Master_Log_File:             Slave_IO_Running: No            Slave_SQL_Running: No                   Last_Errno: 13121                   Last_Error: Relay log read failure: Could not parse relay log event entry. The possible reasons are: the master's binary log is corrupted (you can check this by running 'mysqlbinlog' on the binary log), the slave's relay log is corrupted (you can check this by running 'mysqlbinlog' on the relay log), a network problem, the server was unable to fetch a keyring key required to open an encrypted relay log file, or a bug in the master's or slave's MySQL code. If you want to check the master's binary log or slave's relay log, you will be able to know their names by issuing 'SHOW SLAVE STATUS' on this slave. 
于是查看error log，发现error log中的内容如下：
2021-03-31T11:34:39.367173+08:00 11 [Warning] [MY-010897] [Repl] Storing MySQL user name or password information in the master info repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START SLAVE; see the 'START SLAVE Syntax' in the MySQL Manual for more information.2021-03-31T11:34:39.368161+08:00 12 [ERROR] [MY-010596] [Repl] Error reading relay log event for channel '': binlog truncated in the middle of event; consider out of disk space2021-03-31T11:34:39.368191+08:00 12 [ERROR] [MY-013121] [Repl] Slave SQL for channel '': Relay log read failure: Could not parse relay log event entry. The possible reasons are