mysql 服务器一直在关闭，我正在使用 DigitalOcean 512 MB 内存和 20GB 磁盘。 我正在运行 WordPress 和 iRedMail。这是我的错误日志：
Version: '5.5.38-0ubuntu0.14.04.1' socket: '/var/run/mysqld/mysqld.sock' port$
150202 18:28:47 [Warning] Using unique option prefix myisam-recover instead of $
150202 18:28:47 [Note] Plugin 'FEDERATED' is disabled.
150202 18:28:47 InnoDB: The InnoDB memory heap is disabled
150202 18:28:47 InnoDB: Mutexes and rw_locks use GCC atomic builtins
150202 18:28:47 InnoDB: Compressed tables use zlib 1.2.8
150202 18:28:47 InnoDB: Using Linux native AIO
150202 18:28:47 InnoDB: Initializing buffer pool, size = 128.0M
InnoDB: mmap(137363456 bytes) failed; errno 12
150202 18:28:47 InnoDB: Completed initialization of buffer pool
150202 18:28:47 InnoDB: Fatal error: cannot allocate memory for the buffer pool
150202 18:28:47 [ERROR] Plugin 'InnoDB' init function returned error.
150202 18:28:47 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
150202 18:28:47 [ERROR] Unknown/unsupported storage engine: InnoDB
150202 18:28:47 [ERROR] Aborting
150202 18:28:47 [Note] /usr/sbin/mysqld: Shutdown complete
这是我的 /etc/mysql/my.cnf
#
# The MySQL database server configuration file.
#
# You can copy this to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
#
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html
# This will be passed to all mysql clients
# It has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain "#" chars...
# Remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock
# Here is entries for some specific programs
# The following values assume you have at least 32M ram
# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0
[mysqld]
innodb_file_per_table
#
# * Basic Settings
#
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address = 127.0.0.1
#
# * Fine Tuning
#
key_buffer = 16K
max_allowed_packet = 16K
table_cache = 1
sort_buffer_size = 16K
read_buffer_size = 16K
read_rnd_buffer_size = 1K
net_buffer_length = 1K
thread_stack = 16K
thread_cache_size = 8
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover = BACKUP
#max_connections = 100
#table_cache = 64
#thread_concurrency = 10
#
# * Query Cache Configuration
#
# Set the query cache low
query_cache_limit = 1048576
query_cache_size = 1048576
query_cache_type = 1
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file = /var/log/mysql/mysql.log
#general_log = 1
#
# Error log - should be very few entries.
#
log_error = /var/log/mysql/error.log
#
# Here you can see queries with especially long duration
#log_slow_queries = /var/log/mysql/mysql-slow.log
#long_query_time = 2
#log-queries-not-using-indexes
#
# The following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see README.Debian about
# other settings you may need to change.
#server-id = 1
#log_bin = /var/log/mysql/mysql-bin.log
expire_logs_days = 10
max_binlog_size = 100M
#binlog_do_db = include_database_name
#binlog_ignore_db = include_database_name
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
#
# * Security Features
#
# Read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem
[mysqldump]
quick
quote-names
max_allowed_packet = 16K
[mysql]
no-auto-rehash
# faster start of mysql but no tab completition
[isamchk]
key_buffer = 16K
sort_buffer_size = 16K
[myisamchk]
key_buffer = 16K
sort_buffer_size = 16K
[mysqlhotcopy]
interactive-timeout
#
# * IMPORTANT: Additional settings that can override those from this file!
# The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/mysql/conf.d/
512MB 内存和 20GB 数据对 WordPress 来说是否不够用？如果是，那么我做错了什么？任何帮助都将不胜感激。
答案1
看看这个Stack Overflow 问题（或这个数据库管理员 1)，它处理的是完全相同的情况。 RAM 数量对于 MySQL 来说似乎太小了，您需要配置您的 DB 服务器，甚至可能还需要配置您的 Web 服务器。
此外，如果您没有交换分区，那么您应该有一个（如果可能的话）。
另一条建议：您最好向 Stack Exchange 网站的其他成员询问这个问题，因为这与 Ubuntu 无关。