背景

出于无奈，使用mac本安装了双系统，然后安装的是win10，然后又安装了MySQL。
既然用的windows，我下载的mysql是install版本的，傻瓜式下一步安装法。然后到了最后的配置阶段，MySQL服务无法启动。
然后，各种百度，发现网上的都是什么卸载啊，重装的，简直不要太low！！！
然后有看到了，什么要用源码编译重新安装的，我靠，算了，继续找。
于是继续看文章，发现了一个找问题根源的办法，就是看日志文件，这个真的很重要，对于我们解决问题很有帮助。

如何看日志

1.右键此电脑->管理

2018-09-13_174136.png

2.点击事件查看器

2018-09-13_174337.png

2018-09-13_174656.png

3.然后点击错误，常规和详细信息就是错误信息
然后我们就可以通过错误信息来具体确定到底是什么错误了！

找到MySQL错误信息

由于我的MySQL已经安装好了，并且my.ini配置文件中的日志输出设置都配置了，所以当我启动服务的时候，错误信息会直接输出到一个文件中（在哪里看呢，在C:\ProgramData\MySQL\MySQL Server 5.5\data\DESKTOP-5967RV4.err）这个路径安装的时候默认的，需要在C盘关闭开启隐藏文件功能：
然后打开DESKTOP-5967RV4.err这个文件，

180913 16:41:31 [Note] Plugin 'FEDERATED' is disabled.
180913 16:41:31 InnoDB: The InnoDB memory heap is disabled
180913 16:41:31 InnoDB: Mutexes and rw_locks use Windows interlocked functions
180913 16:41:31 InnoDB: Compressed tables use zlib 1.2.3
180913 16:41:31 InnoDB: Initializing buffer pool, size = 47.0M
180913 16:41:31 InnoDB: Completed initialization of buffer pool
InnoDB: Error: space header page consists of zero bytes in data file .\ibdata1
180913 16:41:31 InnoDB: Could not open or create data files.
180913 16:41:31 InnoDB: If you tried to add new data files, and it failed here,
180913 16:41:31 InnoDB: you should now edit innodb_data_file_path in my.cnf back
180913 16:41:31 InnoDB: to what it was, and remove the new ibdata files InnoDB created
180913 16:41:31 InnoDB: in this failed attempt. InnoDB only wrote those files full of
180913 16:41:31 InnoDB: zeros, but did not yet use them in any way. But be careful: do not
180913 16:41:31 InnoDB: remove old data files which contain your precious data!
180913 16:41:31 [ERROR] Plugin 'InnoDB' init function returned error.
180913 16:41:31 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
180913 16:41:31 [ERROR] Unknown/unsupported storage engine: INNODB
180913 16:41:31 [ERROR] Aborting

然后，我们看到了为什么出启动不了服务：
The InnoDB memory heap is disabled
InnoDB: Error: space header page consists of zero bytes in data file .\ibdata1
Could not open or create data files.
那么这个是什么原因了，就是数据库引擎Innodb没有安装好，就是它不能自动帮我们安装这个引擎了。
当然，英语好的话，错误日志里也提示了我们要配置innodb_data_file_path在my.ini配置文件中，然后删除默认的bdata1文件。

配置好my.ini配置文件

my.ini配置文件的基本配置是着这样的：

[client]

port=3306

[mysql]

default-character-set=utf8


# SERVER SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by the MySQL Server. Make sure that
# you have installed the server correctly (see above) so it reads this 
# file.
#
[mysqld]

# The TCP/IP Port the MySQL Server will listen on
port=3306


#Path to installation directory. All paths are usually resolved relative to this.
#这个是你MySQL安装的路劲
basedir="C:/devlep/mysql/" 

#Path to the database root，数据库文件保存的路劲，日志也会保存在这里
datadir="C:/ProgramData/MySQL/MySQL Server 5.5/Data/"

# The default character set that will be used when a new schema or table is
# created and no character set is defined
character-set-server=utf8

# The default storage engine that will be used when create new tables when
default-storage-engine=INNODB

# Set the SQL mode to strict
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

# The maximum amount of concurrent sessions the MySQL server will
# allow. One of these connections will be reserved for a user with
# SUPER privileges to allow the administrator to login even if the
# connection limit has been reached.
max_connections=100

# Query cache is used to cache SELECT results and later return them
# without actual executing the same query once again. Having the query
# cache enabled may result in significant speed improvements, if your
# have a lot of identical queries and rarely changing tables. See the
# "Qcache_lowmem_prunes" status variable to check if the current value
# is high enough for your load.
# Note: In case your tables change very often or if your queries are
# textually different every time, the query cache may result in a
# slowdown instead of a performance improvement.
query_cache_size=0

# The number of open tables for all threads. Increasing this value
# increases the number of file descriptors that mysqld requires.
# Therefore you have to make sure to set the amount of open files
# allowed to at least 4096 in the variable "open-files-limit" in
# section [mysqld_safe]
table_cache=256

# Maximum size for internal (in-memory) temporary tables. If a table
# grows larger than this value, it is automatically converted to disk
# based table This limitation is for a single table. There can be many
# of them.
tmp_table_size=18M


# How many threads we should keep in a cache for reuse. When a client
# disconnects, the client's threads are put in the cache if there aren't
# more than thread_cache_size threads from before.  This greatly reduces
# the amount of thread creations needed if you have a lot of new
# connections. (Normally this doesn't give a notable performance
# improvement if you have a good thread implementation.)
thread_cache_size=8

#*** MyISAM Specific options

# The maximum size of the temporary file MySQL is allowed to use while
# recreating the index (during REPAIR, ALTER TABLE or LOAD DATA INFILE.
# If the file-size would be bigger than this, the index will be created
# through the key cache (which is slower).
myisam_max_sort_file_size=100G

# If the temporary file used for fast index creation would be bigger
# than using the key cache by the amount specified here, then prefer the
# key cache method.  This is mainly used to force long character keys in
# large tables to use the slower key cache method to create the index.
myisam_sort_buffer_size=35M

# Size of the Key Buffer, used to cache index blocks for MyISAM tables.
# Do not set it larger than 30% of your available memory, as some memory
# is also required by the OS to cache rows. Even if you're not using
# MyISAM tables, you should still set it to 8-64M as it will also be
# used for internal temporary disk tables.
key_buffer_size=25M

# Size of the buffer used for doing full table scans of MyISAM tables.
# Allocated per thread, if a full scan is needed.
read_buffer_size=64K
read_rnd_buffer_size=256K

# This buffer is allocated when MySQL needs to rebuild the index in
# REPAIR, OPTIMZE, ALTER table statements as well as in LOAD DATA INFILE
# into an empty table. It is allocated per thread so be careful with
# large settings.
sort_buffer_size=256K


#*** INNODB Specific options ***
# Use this option if you have a MySQL server with InnoDB support enabled
# but you do not plan to use it. This will save memory and disk space
# and speed up some things.
#skip-innodb

# Additional memory pool that is used by InnoDB to store metadata
# information.  If InnoDB requires more memory for this purpose it will
# start to allocate it from the OS.  As this is fast enough on most
# recent operating systems, you normally do not need to change this
# value. SHOW INNODB STATUS will display the current amount used.
innodb_additional_mem_pool_size=2M

# If set to 1, InnoDB will flush (fsync) the transaction logs to the
# disk at each commit, which offers full ACID behavior. If you are
# willing to compromise this safety, and you are running small
# transactions, you may set this to 0 or 2 to reduce disk I/O to the
# logs. Value 0 means that the log is only written to the log file and
# the log file flushed to disk approximately once per second. Value 2
# means the log is written to the log file at each commit, but the log
# file is only flushed to disk approximately once per second.
innodb_flush_log_at_trx_commit=1

# The size of the buffer InnoDB uses for buffering log data. As soon as
# it is full, InnoDB will have to flush it to disk. As it is flushed
# once per second anyway, it does not make sense to have it very large
# (even with long transactions).
innodb_log_buffer_size=1M

# InnoDB, unlike MyISAM, uses a buffer pool to cache both indexes and
# row data. The bigger you set this the less disk I/O is needed to
# access data in tables. On a dedicated database server you may set this
# parameter up to 80% of the machine physical memory size. Do not set it
# too large, though, because competition of the physical memory may
# cause paging in the operating system.  Note that on 32bit systems you
# might be limited to 2-3.5G of user level memory per process, so do not
# set it too high.
innodb_buffer_pool_size=47M

# Size of each log file in a log group. You should set the combined size
# of log files to about 25%-100% of your buffer pool size to avoid
# unneeded buffer pool flush activity on log file overwrite. However,
# note that a larger logfile size will increase the time needed for the
# recovery process.
innodb_log_file_size=24M

# Number of threads allowed inside the InnoDB kernel. The optimal value
# depends highly on the application, hardware as well as the OS
# scheduler properties. A too high value may lead to thread thrashing.
innodb_thread_concurrency=10

由于这个是官方文档，介绍的很详细，我就不一一解释了。
解决问题很简单：

• 在#* INNODB Specific options *****下加入这样的一条语句：
  innodb_data_file_path = ibdata1:1024M;ibdata2:512M:autoextend
• 加入了这条语句后，将C:\ProgramData\MySQL\MySQL Server 5.5\data\下的文件全部删除，注意删除的是文件，不是文件夹，文件夹是数据库
• 然后重启MySQL服务，发现还是报错了，这就是双系统MMP的地方了，我们还需要在my.ini配置文件中加一条语句
  innodb_flush_method=normal
• 然后，重新启动，解决了！