【发布时间】：2016-02-16 13:47:06
【问题描述】：
有几个关于 MySQL 在运行 XAMPP 时无法启动的问题，但不幸的是我无法从这些问题中找到解决方案。
这是我的情况： 我为 Linux 5.6.14-3 安装了 XAMPP，昨天运行它时一切正常。 今天，我再次运行 XAMPP：
/opt/lampp$ sudo ./xampp start
Starting XAMPP for Linux 5.6.14-3...
XAMPP: Starting Apache...ok.
XAMPP: Starting MySQL...ok.
XAMPP: Starting ProFTPD...ok.
然后我在浏览器中打开 localhost，将我带到 xampp 仪表板。在那里我点击 phpMyAdmin 菜单条目，它给了我：
Error
MySQL said:
Cannot connect: invalid settings.
Connection for controluser as defined in your configuration failed.
phpMyAdmin tried to connect to the MySQL server,
and the server rejected the connection.
You should check the host, username and password
in your configuration and make sure that they
correspond to the information given by the
administrator of the MySQL server.
我认为我确保控制用户拥有正确的通行证。
问题似乎是 MySQL 并没有真正启动，尽管它说“ok”（见上文）。因为，当我停止 XAMPP 时，我得到：
/opt/lampp$ sudo ./xampp stop
Stopping XAMPP for Linux 5.6.14-3...
XAMPP: Stopping Apache...ok.
XAMPP: Stopping MySQL...not running.
XAMPP: Stopping ProFTPD...ok.
查看xampp的error_log，有一个条目，看起来很可疑（虽然我不是很懂），说：
[Sun Nov 15 11:38:59.737875 2015] [mpm_prefork:notice] [pid 6217] AH00169: caught SIGTERM, shutting down
所以，如果有人能够找到问题所在或给我提示以解决问题，我将不胜感激。已经谢谢了！
编辑 - 问题“已修复”（但不知道我到底做了什么）
这是 MySQL 错误日志（位于 /opt/lampp/var/mysql/[computername].err）：
2015-11-15 15:52:44 10864 mysqld_safe Starting mysqld daemon with databases from /opt/lampp/var/
2015-11-15 15:52:44 140410457307008 [Note] Using unique option prefix 'key_buffer' is error-prone and can break in the future. Please use the full name 'key_buffer_size' instead.
2015-11-15 15:52:44 140410457307008 [Note] /opt/lampp/sbin/mysqld (mysqld 10.1.8-MariaDB) starting as process 11011 ...
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Using mutexes to ref count buffer pool pages
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: The InnoDB memory heap is disabled
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Memory barrier is not used
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Compressed tables use zlib 1.2.8
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Using CPU crc32 instructions
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Initializing buffer pool, size = 16.0M
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Completed initialization of buffer pool
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Highest supported file format is Barracuda.
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: The log sequence numbers 3813213 and 3813213 in ibdata files do not match the log sequence number 9929741 in the ib_logfiles!
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Database was not shutdown normally!
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Starting crash recovery.
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Reading tablespace information from the .ibd files...
2015-11-15 15:52:44 140410457307008 [ERROR] InnoDB: Attempted to open a previously opened tablespace. Previous tablespace bitnami_joomla/jos_content_frontpage uses space ID: 14 at filepath: ./bitnami_joomla/jos_content_frontpage.ibd. Cannot open tablespace phpmyadmin/pma__bookmark which uses space ID: 14 at filepath: ./phpmyadmin/pma__bookmark.ibd
2015-11-15 15:52:44 7fb3db6e3780 InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
InnoDB: If you are installing InnoDB, remember that you must create
InnoDB: directories yourself, InnoDB does not create them.
InnoDB: Error: could not open single-table tablespace file ./phpmyadmin/pma__bookmark.ibd
InnoDB: We do not continue the crash recovery, because the table may become
InnoDB: corrupt if we cannot apply the log records in the InnoDB log to it.
InnoDB: To fix the problem and start mysqld:
InnoDB: 1) If there is a permission problem in the file and mysqld cannot
InnoDB: open the file, you should modify the permissions.
InnoDB: 2) If the table is not needed, or you can restore it from a backup,
InnoDB: then you can remove the .ibd file, and InnoDB will do a normal
InnoDB: crash recovery and ignore that table.
InnoDB: 3) If the file system or the disk is broken, and you cannot remove
InnoDB: the .ibd file, you can set innodb_force_recovery > 0 in my.cnf
InnoDB: and force InnoDB to continue crash recovery here.
2015-11-15 15:52:44 10864 mysqld_safe mysqld from pid file /opt/lampp/var/mysql/[computername].pid ended
第一次尝试：我备份了目录/opt/lampp/var/mysql/phpmyadmin/并添加了
innodb_force_recovery = 1
在 /opt/lampp/etc/my.conf 的末尾。再次启动 MySQL 时，这给了我同样的错误。
接下来的尝试是从目录中删除文件 pma__bookmarks.idb，这导致错误现在抱怨 pma__favorites。
最后，我删除了所有 pma__*.idb 文件，瞧！ MySQL 正在运行，我可以访问 phpMyAdmin 页面。
对我有用，但我不知道删除 pma 数据库会丢失什么？ （它们没有以任何方式恢复，看起来......）
可能是数据库文件损坏了，当我的计算机出现故障时，它们仍在运行！？
【问题讨论】：
标签： mysql ubuntu phpmyadmin xampp