title: Cannot allocate memory for the buffer pool
body: <p>We are facing one very serious issue while starting Mysql.
  We are Using Digital Ocean.</p>
  
  <pre><code>Droplet
  RAM = 8GB 
  CPU = 4Core
  Mysql Version = 5.6
  </code></pre>
  
  <p>My.cnf</p>
  
  <pre><code>    [mysql]
      # CLIENT #
      port                           = 3306
      socket                         = /var/lib/mysql/mysql.sock
  
      [mysqld]
      max_connections                = 300
      open_files_limit               = 1024000
      #interactive_timeout           = 30
      #wait_timeout              = 30
      # GENERAL #
      user                           = mysql
      default-storage-engine         = InnoDB
      socket                         = /var/lib/mysql/mysql.sock
      pid-file                       = /var/lib/mysql/mysql.pid
  
      # MyISAM #
      key-buffer-size                = 64M
      myisam-recover                 = FORCE,BACKUP
  
      # SAFETY #
      max-allowed-packet             = 16M
      max-connect-errors             = 1000000
      skip-name-resolve
      sysdate-is-now                 = 1
      innodb                         = FORCE
  
      # DATA STORAGE #
      datadir                        = /var/lib/mysql/
  
      # BINARY LOGGING #
      log-bin                        = /var/lib/mysql/mysql-bin
      expire_logs_days               = 10
      #expire-logs-days              = 14
      sync_binlog                    = 1
  
      # CACHES AND LIMITS #
      tmp-table-size                 = 500M
      max-heap-table-size            = 500M
      query-cache-type               = 0
      query-cache-size               = 64M
      #max-connections                = 300
      thread-cache-size              = 50
      #open_files_limit               = 65535
      table-definition-cache         = 1024M
      table_open_cache               = 600
  
      # INNODB #
      innodb-flush-method            = O_DIRECT
      innodb-log-files-in-group      = 2
      innodb-log-file-size           = 64M
      innodb-flush-log-at-trx-commit = 1
      innodb-file-per-table          = 1
      innodb-buffer-pool-size        = 12000M
      innodb-buffer-pool-instances   = 1
      join_buffer_size               = 6M
  
      # LOGGING #
      log-error                      = /var/lib/mysql/mysql-error.log
      log-queries-not-using-indexes  = 1
      slow-query-log                 = 1
      slow-query-log-file            = /var/lib/mysql/mysql-slow.log
      long-query-time            = 5
      log-queries-not-using-indexes
  </code></pre>
  
  <p>We are able to start Mysql without any error.</p>
  
  <p>But when we resize existing Droplet from 8Gb RAM and 4 CPU to 16GB and 8 CPU and did not make any changes in my.cnf but Unable to start MYSQL.</p>
  
  <p>During starting MySql it consume all memory 16GB RAM and 5GB swap.</p>
  
  <p>It show error. </p>
  
  <pre><code>160910 18:15:03 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql/
      2016-09-10 18:15:32 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
      2016-09-10 18:15:32 0 [Note] /usr/sbin/mysqld (mysqld 5.6.31-log) starting as process 14643 ...
      2016-09-10 18:15:32 14643 [Warning] Buffered warning: option 'table_definition_cache': unsigned value 1073741824 adjusted to 524288
  
      2016-09-10 18:15:32 14643 [Warning] Buffered warning: Could not increase number of max_open_files to more than 1024 (request: 1024000)
  
  2016-09-10 18:15:32 14643 [Warning] Buffered warning: Changed limits: max_connections: 214 (requested 300)
  
  2016-09-10 18:15:32 14643 [Warning] Buffered warning: Changed limits: table_open_cache: 400 (requested 600)
  
  2016-09-10 18:15:32 14643 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead.
  2016-09-10 18:15:32 14643 [Note] Plugin 'FEDERATED' is disabled.
  2016-09-10 18:15:32 14643 [Warning] The option innodb (skip-innodb) is deprecated and will be removed in a future release
  2016-09-10 18:15:32 14643 [Note] InnoDB: Using atomics to ref count buffer pool pages
  2016-09-10 18:15:32 14643 [Note] InnoDB: The InnoDB memory heap is disabled
  2016-09-10 18:15:32 14643 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
  2016-09-10 18:15:32 14643 [Note] InnoDB: Memory barrier is not used
  2016-09-10 18:15:32 14643 [Note] InnoDB: Compressed tables use zlib 1.2.3
  2016-09-10 18:15:32 14643 [Note] InnoDB: Using Linux native AIO
  2016-09-10 18:15:32 14643 [Note] InnoDB: Using CPU crc32 instructions
  2016-09-10 18:15:32 14643 [Note] InnoDB: Initializing buffer pool, size = 7.8G
  InnoDB: mmap(8585216000 bytes) failed; errno 12
  2016-09-10 18:15:32 14643 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
  2016-09-10 18:15:32 14643 [ERROR] Plugin 'InnoDB' init function returned error.
  2016-09-10 18:15:32 14643 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
  2016-09-10 18:15:32 14643 [ERROR] Failed to initialize plugins.
  2016-09-10 18:15:32 14643 [ERROR] Aborting
  2016-09-10 18:15:32 14643 [Note] Binlog end
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'partition'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'PERFORMANCE_SCHEMA'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_DATAFILES'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_TABLESPACES'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN_COLS'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_FIELDS'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_COLUMNS'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_INDEXES'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_TABLESTATS'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_SYS_TABLES'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_FT_INDEX_TABLE'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_FT_INDEX_CACHE'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_FT_CONFIG'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_FT_BEING_DELETED'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_FT_DELETED'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_FT_DEFAULT_STOPWORD'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_METRICS'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_BUFFER_POOL_STATS'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE_LRU'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX_RESET'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_CMPMEM_RESET'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_CMPMEM'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_CMP_RESET'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_CMP'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_LOCK_WAITS'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_LOCKS'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'INNODB_TRX'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'BLACKHOLE'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'ARCHIVE'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'MRG_MYISAM'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'MyISAM'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'MEMORY'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'CSV'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'sha256_password'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'mysql_old_password'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'mysql_native_password'
  2016-09-10 18:15:32 14643 [Note] Shutting down plugin 'binlog'
  2016-09-10 18:15:32 14643 [Note] /usr/sbin/mysqld: Shutdown complete
  160910 18:15:33 mysqld_safe mysqld from pid file /var/lib/mysql/mysql.pid ended
  </code></pre>
  
  <p>I am not able to understand why mysql is not able to start even there is no change in any setting. </p>
  
  <p>I have 5GB of Swap memory. </p>
  
  <p>According to me I think its issue with DigitalOcean reason same config is working on 8GB ram but it did not work on 16Gb RAM but they are claiming there is no issue on 16GB droplet. </p>
  
  <p>Free -m say before starting MySQL</p>
  
  <pre><code> total        used        free      shared  buff/cache   available
  Mem:          16047         122       15843           1          81       15792
  Swap:          2047          38        2009
  Total:        18095         160       17853
  </code></pre>
  
  <p>uname -a</p>
  
  <pre><code>3.10.0-327.10.1.el7.x86_64 #1 SMP Tue Feb 16 17:03:50 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
  </code></pre>
  
  <p>Also I would to mentioned that we have installed only mysql no other service. </p>
  
  <p>Please help to get it resolved.</p>
  
  <p>Thanks</p>