Hi, All we use MariaDB 10.1.16 , about have 30 machines. Recently ,there one master and slave's ibdat1 growed to about 4GB, others machine are normal. mainly parameter in my.cnf : innodb_data_home_dir = /data/mysql/data innodb_data_file_path = ibdata1:2G:autoextend innodb_log_files_in_group=3 innodb_log_file_size = 1G innodb_undo_logs=128 innodb_undo_tablespaces=4 innodb_file_per_table= 1 ls -l /data/mysql/data -rw-r--r-- 1 mysql mysql 4429185024 Aug 25 21:38 ibdata1 -rw-r--r-- 1 mysql mysql 1073741824 Aug 25 21:38 ib_logfile0 -rw-r--r-- 1 mysql mysql 1073741824 Aug 25 21:38 ib_logfile1 -rw-r--r-- 1 mysql mysql 1073741824 Aug 25 20:13 ib_logfile2 -rw-r--r-- 1 mysql mysql 616562688 Aug 25 21:36 undo001 -rw-r--r-- 1 mysql mysql 411041792 Aug 25 21:27 undo002 -rw-r--r-- 1 mysql mysql 708837376 Aug 25 21:34 undo003 -rw-r--r-- 1 mysql mysql 981467136 Aug 25 21:34 undo004 Today, when found the problem, there are not some big transaction in show processlist. We guess ibdata1 had growed to 4GB in previous some time, but we want to know how confirm the cause and shrink ibdate1 file ? Thank . -- Ljr