Amazon EC2, mysql aborting start because InnoDB: mmap (x bytes) failed; errno 12

Question

I have set up a micro instance server on EC2 based MySQL server fails frequently and for the third time, MySQL server is gone. The logs only show 120423 09:13:38 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended 120423 09:14:27 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql 120423 9:14:27 [Note] Plugin 'FEDERATED' is disabled. 120423 9:14:27 InnoDB: The InnoDB memory heap is disabled 120423 9:14:27 InnoDB: Mutexes and rw_locks use GCC atomic builtins 120423 9:14:27 InnoDB: Compressed tables use zlib 1.2.3 120423 9:14:27 InnoDB: Using Linux native AIO 120423 9:14:27 InnoDB: Initializing buffer pool, size = 512.0M InnoDB: mmap(549453824 bytes) failed; errno 12 120423 9:14:27 InnoDB: Completed initialization of buffer pool 120423 9:14:27 InnoDB: Fatal error: cannot allocate memory for the buffer pool 120423 9:14:27 [ERROR] Plugin 'InnoDB' init function returned error. 120423 9:14:27 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 120423 9:14:27 [ERROR] Unknown/unsupported storage engine: InnoDB 120423 9:14:27 [ERROR] Aborting What is really failed; errno 12? And how could I give more space/memory or whatever needed to make this fixed. I fix this each time by rebooting the whole system and deleting all logs and restart the MySQL server. But I know something is wrong with my configuration. Also, my `my.cnf' is like below : [mysqld] # Settings user and group are ignored when systemd is used. # If you need to run mysqld under different user or group, # customize your systemd unit file for mysqld according to the # instructions in http://fedoraproject.org/wiki/Systemd # max_allowed_packet=500M datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 innodb_buffer_pool_size = 512M [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid Select the correct answer from above options

Answer 1

A default SWAP space for micro instance is not available. So, you have to set up a swap space for your micro instance to avoid crashes. Micro instances have only 613MB of memory, so MySQL might crash quite often. Setting up a swap space can provide better performance. Follow the below steps to create a swap space for your micro instance. First, create an AWS account and run a Micro instance to start with. Follow these steps to create a swap space for your running micros instance. First, create an AWS account and run a micro instance to begin with. Run dd if=/dev/zero of=/swapfile bs=1M count=1024 Run mkswap /swapfile Run swapon /swapfile Add this line /swapfile swap swap defaults 0 0 to /etc/fstab If you want to automatically enable swap file after every reboot, then you can do the fourth step. Few commands related to SWAP space: $ swapon -s $ free -k $ swapoff -a $ swapon -a