Similar crash with same Assertion Failure message was encountered a few days ago. Server version: 5.6.22-71.0-log Percona Server (GPL), Release 71.0, Revision 726 2015-09-24 11:13:07 7f612f8bc700 InnoDB: Assertion failure in thread 140055386244864 in file os0file.cc line 5126 InnoDB: Failing assertion: slot != NULL InnoDB: We intentionally generate a memory trap. InnoDB: Submit a detailed bug report to http://bugs.mysql.com. InnoDB: If you get repeated assertion failures or crashes, even InnoDB: immediately after the mysqld startup, there may be InnoDB: corruption in the InnoDB tablespace. Please refer to InnoDB: http://dev.mysql.com/doc/refman/5.6/en/forcing-innodb-recovery.html InnoDB: about forcing recovery. 05:43:07 UTC - mysqld got signal 6 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. Please help us make Percona Server better by reporting any bugs at http://bugs.percona.com/ key_buffer_size=1073741824 read_buffer_size=131072 max_used_connections=126 max_threads=1202 thread_count=7 connection_count=5 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1527811 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. Thread pointer: 0x0 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = 0 thread_stack 0x40000 /usr/sbin/mysqld(my_print_stacktrace+0x2c)[0x9091dc] /usr/sbin/mysqld(handle_fatal_signal+0x352)[0x662482] /lib/x86_64-linux-gnu/libpthread.so.0(+0x10340)[0x7f909a1cb340] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x39)[0x7f9099821bb9] /lib/x86_64-linux-gnu/libc.so.6(abort+0x148)[0x7f9099824fc8] /usr/sbin/mysqld[0x98a2fb] /usr/sbin/mysqld[0xa9dfb5] /usr/sbin/mysqld[0x9f2d15] /lib/x86_64-linux-gnu/libpthread.so.0(+0x8182)[0x7f909a1c3182] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7f90998e5efd] You may download the Percona Server operations manual by visiting http://www.percona.com/software/percona-server/. You may find information in the manual which will help you identify the cause of the crash. 150924 11:13:07 mysqld_safe Number of processes running now: 0 150924 11:13:07 mysqld_safe mysqld restarted However as specified in the reproducible case disk space wasnt a constraint. There was more than 100G space remaining on the mysql datadir volume. Below is the my.cnf [mysql] port = 3306 socket = /dbvol/mysql/var/run/mysqld/mysqld.sock [mysqld] user = mysql default-storage-engine = InnoDB socket = /dbvol/mysql/var/run/mysqld/mysqld.sock pid-file = /dbvol/mysql/var/run/mysqld/mysqld.pid key-buffer-size = 1G myisam-recover = FORCE,BACKUP max-allowed-packet = 512M max-connect-errors = 1000000 datadir = /dbvol/mysql/lib/mysql/ binlog-format = STATEMENT log-bin = /dbvol/mysql/lib/mysql/mysql-bin expire-logs-days = 21 sync-binlog = 1 read-only = 0 skip-slave-start = 1 log-slave-updates = 0 relay-log = /dbvol/mysql/lib/mysql/relay-bin slave-net-timeout = 60 sync-master-info = 10000 sync-relay-log-info = 10000 server-id = 21300 tmp-table-size = 32M max-heap-table-size = 32M query-cache-type = 0 max-connections = 1200 thread-cache-size = 600 open-files-limit = 65535 table-definition-cache = 4096 table-open-cache-instances = 16 table-open-cache = 1500 innodb-flush-method = O_DIRECT innodb-log-files-in-group = 2 innodb-log-file-size = 512M innodb-flush-log-at-trx-commit = 1 innodb-file-per-table = 1 innodb-buffer-pool-size = 180G innodb_log_buffer_size = 32M innodb-buffer-pool-instances=12 innodb_io_capacity = 2000 innodb-flush-neighbors = 0 log-error = /dbvol/mysql/log/mysql-error.log log-queries-not-using-indexes = 1 slow-query-log = 1 slow-query-log-file = /dbvol/mysql/log/mysql-slow.log long_query_time = 5 slow_query_log_use_global_control = log_slow_rate_limit log_slow_rate_limit = 100 The server doesnt have SWAP configured, would it be something which can also cause such an assertion ? There were OOM kill message either. This has similar occurred on couple of other slaves with versions, 5.6.21-70.1-log Percona Server (GPL), Release 70.1, Revision 698 5.6.22-71.0-log Percona Server (GPL), Release 71.0, Revision 726