某台mysql數據庫，突然掉電，重啟系統啟動數據庫失敗，進入數據庫目錄發現數據文件完好，從新初始化數據庫，從數據文件中恢復數據
一、將/home/mysql-5.7.26/data/目錄復制出來
[root@orderer home]# cd mysql-5.7.26/ [root@orderer mysql-5.7.26]# cp -R data/ ../data_bak
二、刪除/home/mysql-5.7.26/data/目錄，因為初始化數據庫的時候，data目錄必須為空
[root@orderer mysql-5.7.26]# rm -rf data/ [root@orderer mysql-5.7.26]# mkdir data
由於我是root賬戶操作的，所以將data目錄權限賦予mysql用戶
[root@orderer mysql-5.7.26]# chown -R mysql:mysql data
三、重新初始化數據庫
[root@orderer home]# mysqld_safe --defaults-file=/etc/mysql/my.cnf --initialize --basedir=/home/mysql-5.7.26/ --datadir=/home/mysql-5.7.26/data/ 2020-01-19T07:11:22.220590Z mysqld_safe Logging to '/home/mysql-5.7.26/log/mysqld.log'. 2020-01-19T07:11:22.266396Z mysqld_safe Starting mysqld daemon with databases from /home/mysql-5.7.26/data 2020-01-19T07:11:33.111853Z mysqld_safe mysqld from pid file /home/mysql-5.7.26/run/mysqld.pid ended
此時，查看data目錄下已經生成了相關文件
[root@orderer mysql-5.7.26]# ll data ??? 110668 -rw-r----- 1 mysql mysql 56 1? 19 15:11 auto.cnf -rw------- 1 mysql mysql 1680 1? 19 15:11 ca-key.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 ca.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 client-cert.pem -rw------- 1 mysql mysql 1680 1? 19 15:11 client-key.pem -rw-r----- 1 mysql mysql 419 1? 19 15:11 ib_buffer_pool -rw-r----- 1 mysql mysql 12582912 1? 19 15:11 ibdata1 -rw-r----- 1 mysql mysql 50331648 1? 19 15:11 ib_logfile0 -rw-r----- 1 mysql mysql 50331648 1? 19 15:11 ib_logfile1 -rw-r----- 1 mysql mysql 177 1? 19 15:11 master-18-69.000001 -rw-r----- 1 mysql mysql 22 1? 19 15:11 master-18-69.index drwxr-x--- 2 mysql mysql 4096 1? 19 15:11 mysql drwxr-x--- 2 mysql mysql 8192 1? 19 15:11 performance_schema -rw------- 1 mysql mysql 1680 1? 19 15:11 private_key.pem -rw-r--r-- 1 mysql mysql 452 1? 19 15:11 public_key.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 server-cert.pem -rw------- 1 mysql mysql 1676 1? 19 15:11 server-key.pem drwxr-x--- 2 mysql mysql 8192 1? 19 15:11 sys
查找mysql.log日志過濾"temporary password"，得到系統生成的初始隨機密碼，第一次登陸使用
[root@orderer mysql-5.7.26]# cat /home/mysql-5.7.26/log/mysqld.log|grep 'temporary password' 2020-01-19T07:11:25.453456Z 1 [Note] A temporary password is generated for root@localhost: PcrY;58llX3<
四、啟動mysql
[root@orderer home]# mysqld_safe --defaults-file=/etc/mysql/my.cnf 2020-01-19T07:16:34.019182Z mysqld_safe Logging to '/home/mysql-5.7.26/log/mysqld.log'. 2020-01-19T07:16:34.065328Z mysqld_safe Starting mysqld daemon with databases from /home/mysql-5.7.26/data
連接mysql，使用初始隨機密碼登陸
[root@orderer mysql-5.7.26]# mysql -uroot -p -S /home/mysql-5.7.26/mysql.sock Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 10 Server version: 5.7.26-log Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
五、修改root密碼
mysql> alter user 'root'@'localhost' identified by 'xxxxxxx'; Query OK, 0 rows affected (0.01 sec) mysql> flush privileges; Query OK, 0 rows affected (0.01 sec) mysql>
使用新密碼重新登錄
[root@orderer mysql-5.7.26]# mysql -uroot -p -S /home/mysql-5.7.26/mysql.sock Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 14 Server version: 5.7.26-log Source distribution Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 4 rows in set (0.01 sec) mysql>
允許root遠程登陸
[root@push-5-222 /]# mysql -uroot -p -S /home/mysql-5.7.26/mysql.sock Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 5 Server version: 5.7.26 MySQL Community Server (GPL) Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> use mysql; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> update user set host='%' where user='root'; Query OK, 1 row affected (0.00 sec) Rows matched: 1 Changed: 1 Warnings: 0 mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) mysql>
此時，看到數據庫只有mysql，接下來，我們停掉mysql服務
[root@orderer mysql-5.7.26]# mysqladmin -uroot -p -S /home/mysql-5.7.26/mysql.sock shutdown Enter password: [root@orderer mysql-5.7.26]#
六、將備份的數據文件中的數據庫目錄文件夾test復制到data目錄下
[root@orderer mysql-5.7.26]# cp -r ../data_bak/test/ data/
查看data目錄
[root@orderer mysql-5.7.26]# ll data/ ??? 110672 -rw-r----- 1 mysql mysql 56 1? 19 15:11 auto.cnf -rw------- 1 mysql mysql 1680 1? 19 15:11 ca-key.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 ca.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 client-cert.pem -rw------- 1 mysql mysql 1680 1? 19 15:11 client-key.pem -rw-r----- 1 mysql mysql 356 1? 19 15:23 ib_buffer_pool -rw-r----- 1 mysql mysql 12582912 1? 19 15:23 ibdata1 -rw-r----- 1 mysql mysql 50331648 1? 19 15:23 ib_logfile0 -rw-r----- 1 mysql mysql 50331648 1? 19 15:11 ib_logfile1 -rw-r----- 1 mysql mysql 177 1? 19 15:11 master-18-69.000001 -rw-r----- 1 mysql mysql 573 1? 19 15:23 master-18-69.000002 -rw-r----- 1 mysql mysql 44 1? 19 15:16 master-18-69.index drwxr-x--- 2 mysql mysql 4096 1? 19 15:11 mysql drwxr-x--- 2 mysql mysql 8192 1? 19 15:11 performance_schema -rw------- 1 mysql mysql 1680 1? 19 15:11 private_key.pem -rw-r--r-- 1 mysql mysql 452 1? 19 15:11 public_key.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 server-cert.pem -rw------- 1 mysql mysql 1676 1? 19 15:11 server-key.pem drwxr-x--- 2 mysql mysql 8192 1? 19 15:11 sys drwxr-x--- 2 root root 202 1? 19 15:24 test
test目錄已經復制過來，因為是用root賬戶復制的，所以這里將文件所有者變更為mysql
[root@orderer mysql-5.7.26]# chown -R mysql:mysql data/test/ [root@orderer mysql-5.7.26]# ll data ??? 110672 -rw-r----- 1 mysql mysql 56 1? 19 15:11 auto.cnf -rw------- 1 mysql mysql 1680 1? 19 15:11 ca-key.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 ca.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 client-cert.pem -rw------- 1 mysql mysql 1680 1? 19 15:11 client-key.pem -rw-r----- 1 mysql mysql 356 1? 19 15:23 ib_buffer_pool -rw-r----- 1 mysql mysql 12582912 1? 19 15:23 ibdata1 -rw-r----- 1 mysql mysql 50331648 1? 19 15:23 ib_logfile0 -rw-r----- 1 mysql mysql 50331648 1? 19 15:11 ib_logfile1 -rw-r----- 1 mysql mysql 177 1? 19 15:11 master-18-69.000001 -rw-r----- 1 mysql mysql 573 1? 19 15:23 master-18-69.000002 -rw-r----- 1 mysql mysql 44 1? 19 15:16 master-18-69.index drwxr-x--- 2 mysql mysql 4096 1? 19 15:11 mysql drwxr-x--- 2 mysql mysql 8192 1? 19 15:11 performance_schema -rw------- 1 mysql mysql 1680 1? 19 15:11 private_key.pem -rw-r--r-- 1 mysql mysql 452 1? 19 15:11 public_key.pem -rw-r--r-- 1 mysql mysql 1112 1? 19 15:11 server-cert.pem -rw------- 1 mysql mysql 1676 1? 19 15:11 server-key.pem drwxr-x--- 2 mysql mysql 8192 1? 19 15:11 sys drwxr-x--- 2 mysql mysql 202 1? 19 15:24 test
再次啟動mysql服務，並連接mysql,查看數據庫
[root@orderer mysql-5.7.26]# mysql -uroot -p -S /home/mysql-5.7.26/mysql.sock Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 3 Server version: 5.7.26-log Source distribution Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | test | +--------------------+ 5 rows in set (0.00 sec) mysql>
發現已經出現了test數據庫，我們切換到test,並查看表
mysql> use test; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> show tables; +----------------+ | Tables_in_test | +----------------+ | t_product_item | | test | +----------------+ 2 rows in set (0.00 sec)
可以看到數據庫中的表，我們查詢一個表
mysql> select * from test; ERROR 1146 (42S02): Table 'test.test' doesn't exist mysql>
此時，報錯，表不存在，這是因為我們沒有將備份的data目錄下的ibdata1文件復制過來的原因，數據庫引擎使用innodb時，ibdata1文件保存了數據庫元數據信息，里面保存了每個數據庫里的每個表的ID
所以，我們接下來將備份的data目錄下的ibdata1復制到新的數據庫data目錄下覆蓋
七、將備份data目錄下的ibdata1文件復制到新數據庫data目錄下並覆蓋
停掉mysql
[root@orderer mysql-5.7.26]# mysqladmin -uroot -p -S /home/mysql-5.7.26/mysql.sock shutdown Enter password: [root@orderer mysql-5.7.26]#
復制備份data目錄下的ibdata1文件到數據庫data目錄下，提示是否覆蓋，輸入y
[root@orderer mysql-5.7.26]# cp ../data_bak/ibdata1 data/ cp:????"data/ibdata1"? y [root@orderer mysql-5.7.26]#
我們再次啟動mysql，並連接mysql
[root@orderer home]# mysqld_safe --defaults-file=/etc/mysql/my.cnf 2020-01-19T07:36:22.526939Z mysqld_safe Logging to '/home/mysql-5.7.26/log/mysqld.log'. 2020-01-19T07:36:22.574112Z mysqld_safe Starting mysqld daemon with databases from /home/mysql-5.7.26/data
[root@orderer mysql-5.7.26]# mysql -uroot -p -S /home/mysql-5.7.26/mysql.sock Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.7.26-log Source distribution Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
打開test數據庫，並查看表
mysql> use test; Database changed mysql> show tables; +----------------+ | Tables_in_test | +----------------+ | t_product_item | | test | +----------------+ 2 rows in set (0.00 sec) mysql>
再查詢test表
mysql> select * from test; +------+--------+ | id | name | +------+--------+ | 1 | aaaaa | | 2 | bbbb | | 3 | ccccc | | 4 | dddddd | | 5 | eeeeee | | 6 | fffff | | 7 | rrrrr | | 8 | uuuuuu | | 10 | eerrrr | +------+--------+ 9 rows in set (0.00 sec) mysql>
數據庫可以正常讀取了，我們再插入一條數據
mysql> insert into test values(11,'hhhhhh'); Query OK, 1 row affected (0.03 sec)
成功，查詢
mysql> select * from test; +------+--------+ | id | name | +------+--------+ | 1 | aaaaa | | 2 | bbbb | | 3 | ccccc | | 4 | dddddd | | 5 | eeeeee | | 6 | fffff | | 7 | rrrrr | | 8 | uuuuuu | | 10 | eerrrr | | 11 | hhhhhh | +------+--------+ 10 rows in set (0.00 sec) mysql>
可以正常讀寫，至此數據文件恢復數據完成。