問題一 Table xx is marked as crashed and last (automatic?) repair failed
有開發找到我，說數據庫壞了，連不上數據庫，看了下 MySQL 的錯誤日志，報錯如下：
Error: Table './db_name/table_name' is marked as crashed and last (automatic?) repair failed
修復
1、先停止 MySQL：service mysqld stop
2、進入到 MySQL 數據庫的文件存放目錄，比如 cd /data/mysql_data/xx_db
然后執行如下命令：
myisamchk --safe-recover -f -r *.MYI
執行完成后，為了保險起見，我們要將文件的權限改回 MySQL 的運行賬號(自行查看)，比如 mysql：
chown -R mysql:mysql .
3、啟動 MySQL：service mysqld start
4、最后，執行再次自動修復優化命令即可解決：
mysqlcheck --auto-repair --optimize --all-databases -p密碼
問題二 /usr/local/mysql/bin/mysqld does not exist or is not executable.
]# /data/wapage/hhzk/mserver/mysql5713/bin/mysqld_safe --defaults-file=/etc/my.cnf &
[1] 24527
]# 2020-11-23T10:36:45.803151Z mysqld_safe Logging to '/data/wapage/hhzk/mserver/mysql5713/data/qd01-tech2-rec-build001.ps.easou.com.err'.
2020-11-23T10:36:45.809116Z mysqld_safe The file /usr/local/mysql/bin/mysqld
does not exist or is not executable. Please cd to the mysql installation
directory and restart this script from there as follows:
./bin/mysqld_safe&
See http://dev.mysql.com/doc/mysql/en/mysqld-safe.html for more information
[1]+ Exit 1 /data/wapage/hhzk/mserver/mysql5713/bin/mysqld_safe --defaults-file=/etc/my.cnf
說明：mysqld_safe啟動腳本默認的從/usr/local/mysql目錄中讀取另外一個啟動腳本mysqld，因為我的安裝目錄為/data/wapage/hhzk/mserver/mysql5713。所以找不到相關文件。可以從兩個方面解決。
方法一：在/usr/local/mysql創建鏈接文件
mkdir -p /usr/local/mysql/bin
ln -s /data/wapage/hhzk/mserver/mysql5713/bin/mysqld /usr/local/mysql/bin/mysqld
方法二：將mysqld_safe中的所有/usr/local/mysql目錄改為自己實際的安裝目錄
sed -i 's#/usr/local/mysql#/data/wapage/hhzk/mserver/mysql5713#g' /data/wapage/hhzk/mserver/mysql5713/bin/mysqld_safe