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xampp。然后到了最后的配置阶段，MySQL服务无法启动。然后，继续搜索和寻找各种文章，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 
2.点击事件查看器
进入Windos日志->应用程序，找到来源是MySQL 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:\xampp\mysql\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:/xampp/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:/xampp/mysql/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。可以直接拷入my.ini文件。 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:\xampp\mysql\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！