运行在容器里的 MySQL 删除数据目录依然可以正常使用？

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这是一个创建于 1642 天前的主题，其中的信息可能已经有所发展或是发生改变。

运行在容器里的 MySQL 删除数据目录依然可以正常使用，这是什么原因？同样的步骤在虚拟机操作，MySQL 就无法正常使用。

操作步骤如下：

// 创建 mysql 挂载目录 root@aliyun:~# mkdir /data/mysql // 启动一个 mysql root@aliyun:~# docker run -p 3306:3306 -v /data/mysql:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 -d mysql root@aliyun:~# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 5a27786e1657 mysql "docker-entrypoint.s…" 32 seconds ago Up 31 seconds 0.0.0.0:3306->3306/tcp, 33060/tcp relaxed_jang // 进入 mysql 容器 root@aliyun:~# docker exec -it 5a27786e1657 /bin/bash root@5a27786e1657:/# ls /var/lib/mysql/ '#ib_16384_0.dblwr' auto.cnf binlog.index client-cert.pem ib_logfile0 ibtmp1 performance_schema server-cert.pem undo_001 '#ib_16384_1.dblwr' binlog.000001 ca-key.pem client-key.pem ib_logfile1 mysql private_key.pem server-key.pem undo_002 '#innodb_temp' binlog.000002 ca.pem ib_buffer_pool ibdata1 mysql.ibd public_key.pem sys // 删除容器里的 mysql 数据目录 root@5a27786e1657:/# rm -rf /var/lib/mysql/ rm: cannot remove '/var/lib/mysql/': Device or resource busy root@5a27786e1657:/# ls /var/lib/mysql/ root@5a27786e1657:/# exit root@aliyun:~# ifconfig eth0 eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 172.17.17.108 netmask 255.255.192.0 broadcast 172.17.63.255 ether 00:16:3e:00:46:06 txqueuelen 1000 (Ethernet) RX packets 3678 bytes 638716 (638.7 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 3294 bytes 1044025 (1.0 MB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 root@aliyun:~# netstat -nltup|grep 3306 tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 1329/docker-proxy // 删除 mysql 数据目录后，可以正常创建一个测试库 foobar root@aliyun:~# mysql -uroot -p123456 -h172.17.17.108 -P 3306 -e "create database foobar;show databases;" mysql: [Warning] Using a password on the command line interface can be insecure. +--------------------+ | Database | +--------------------+ | foobar | | information_schema | | mysql | | performance_schema | | sys | | test | +--------------------+ root@aliyun:~# ls /data/mysql/ foobar root@aliyun:~# ls /data/mysql/foobar/ root@aliyun:~#

1 条回复

awker

2021-04-20 14:47:31 +08:00

可以看到其实文件描述符还是存在的
# lsof -p 1405|grep deleted
mysqld 1405 999 9uW REG 252,1 50331648 1442005 /var/lib/mysql/ib_logfile1 (deleted)
mysqld 1405 999 10uW REG 252,1 196608 1442006 /var/lib/mysql/#ib_16384_0.dblwr (deleted)
mysqld 1405 999 11uW REG 252,1 8585216 1442007 /var/lib/mysql/#ib_16384_1.dblwr (deleted)
mysqld 1405 999 12uW REG 252,1 16777216 1442009 /var/lib/mysql/undo_001 (deleted)
mysqld 1405 999 13u REG 0,47 0 1442013 /tmp/ibI2pqU8 (deleted)
mysqld 1405 999 14uW REG 252,1 16777216 1442011 /var/lib/mysql/undo_002 (deleted)
mysqld 1405 999 15uW REG 252,1 12582912 1442015 /var/lib/mysql/ibtmp1 (deleted)
mysqld 1405 999 16uW REG 252,1 31457280 1442008 /var/lib/mysql/mysql.ibd (deleted)
mysqld 1405 999 24w RE 252,1 532 1442321 /var/lib/mysql/binlog.000002 (deleted)
mysqld 1405 999 26uW REG 252,1 81920 1442016 /var/lib/mysql/#innodb_temp/temp_1.ibt (deleted)
mysqld 1405 999 27uW REG 252,1 81920 1442017 /var/lib/mysql/#innodb_temp/temp_2.ibt (deleted)
mysqld 1405 999 28uW REG 252,1 81920 1442018 /var/lib/mysql/#innodb_temp/temp_3.ibt (deleted)
mysqld 1405 999 29uW REG 252,1 81920 1442019 /var/lib/mysql/#innodb_temp/temp_4.ibt (deleted)
mysqld 1405 999 30uW REG 252,1 81920 1442020 /var/lib/mysql/#innodb_temp/temp_5.ibt (deleted)
mysqld 1405 999 31uW REG 252,1 81920 1442021 /var/lib/mysql/#innodb_temp/temp_6.ibt (deleted)
mysqld 1405 999 32uW REG 252,1 81920 1442022 /var/lib/mysql/#innodb_temp/temp_7.ibt (deleted)
mysqld 1405 999 33uW REG 252,1 81920 1442023 /var/lib/mysql/#innodb_temp/temp_8.ibt (deleted)
mysqld 1405 999 34uW REG 252,1 81920 1442024 /var/lib/mysql/#innodb_temp/temp_9.ibt (deleted)
mysqld 1405 999 35uW REG 252,1 81920 1442315 /var/lib/mysql/#innodb_temp/temp_10.ibt (deleted)