MySQL umask 导致备份报错
但MySQL对于新创建的数据库目录的权限为 700；数据表文件为660；这可让我们摸不著头脑啦。难道MySQL不依赖系统自己设定的值？参考
备份工具仅限于xtrabackup（2.0+）
umask 大家并不陌生，它设定的文件（目录）的默认权限；一般新创建的目录权限为755，，文件为644；
但MySQL对于新创建的数据库目录的权限为 700；数据表文件为660；这可让我们摸不著头脑啦。难道MySQL不依赖系统自己设定的值？参考文档：MySQL UMASK 决定数据库目录、文件权限是由两个变量UMASK UMASK_DIR 来决定，UMASK 与 Linux中 umask恰好相反，Linux是规定umask 是权限的反向掩码，而UMASK 规定多少其权限就是多少；
可设置UMASK UMASK_DIR 这两个选项来设定MySQL创建文件的默认权限（需重启MySQL）；
为什么MySQL要自己控制一些变量，来实现权限控制（这就不得而知了，可能会安全有关）？
由UMASK 引起的注意事项：
备份：使用xtrabackup 备份的时候，系统用户如果不是 root 或者mysql，它只备份那些有权限进入的数据库目录，没有权限的它还不会报错，ca（如果备份的第一个数据库目录就没有进入权限，就会直接报错）
解决方式：修改数据库目录权限为755，或者更改UMASK_DIR值；
相关阅读：
MySQL备份和恢复具体实施
MySQL备份与恢复的三种方法总结
MySQL备份还原(视图、存储过程)
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
iOS 18 adds a new 'Recovered' album function to retrieve lost or damaged photos
Jul 18, 2024 am 05:48 AM
Apple's latest releases of iOS18, iPadOS18 and macOS Sequoia systems have added an important feature to the Photos application, designed to help users easily recover photos and videos lost or damaged due to various reasons. The new feature introduces an album called "Recovered" in the Tools section of the Photos app that will automatically appear when a user has pictures or videos on their device that are not part of their photo library. The emergence of the "Recovered" album provides a solution for photos and videos lost due to database corruption, the camera application not saving to the photo library correctly, or a third-party application managing the photo library. Users only need a few simple steps
How does Hibernate implement polymorphic mapping?
Apr 17, 2024 pm 12:09 PM
Hibernate polymorphic mapping can map inherited classes to the database and provides the following mapping types: joined-subclass: Create a separate table for the subclass, including all columns of the parent class. table-per-class: Create a separate table for subclasses, containing only subclass-specific columns. union-subclass: similar to joined-subclass, but the parent class table unions all subclass columns.
Detailed tutorial on establishing a database connection using MySQLi in PHP
Jun 04, 2024 pm 01:42 PM
How to use MySQLi to establish a database connection in PHP: Include MySQLi extension (require_once) Create connection function (functionconnect_to_db) Call connection function ($conn=connect_to_db()) Execute query ($result=$conn->query()) Close connection ( $conn->close())
How to handle database connection errors in PHP
Jun 05, 2024 pm 02:16 PM
To handle database connection errors in PHP, you can use the following steps: Use mysqli_connect_errno() to obtain the error code. Use mysqli_connect_error() to get the error message. By capturing and logging these error messages, database connection issues can be easily identified and resolved, ensuring the smooth running of your application.
An in-depth analysis of how HTML reads the database
Apr 09, 2024 pm 12:36 PM
HTML cannot read the database directly, but it can be achieved through JavaScript and AJAX. The steps include establishing a database connection, sending a query, processing the response, and updating the page. This article provides a practical example of using JavaScript, AJAX and PHP to read data from a MySQL database, showing how to dynamically display query results in an HTML page. This example uses XMLHttpRequest to establish a database connection, send a query and process the response, thereby filling data into page elements and realizing the function of HTML reading the database.
How to use database callback functions in Golang?
Jun 03, 2024 pm 02:20 PM
Using the database callback function in Golang can achieve: executing custom code after the specified database operation is completed. Add custom behavior through separate functions without writing additional code. Callback functions are available for insert, update, delete, and query operations. You must use the sql.Exec, sql.QueryRow, or sql.Query function to use the callback function.
How to connect to remote database using Golang?
Jun 01, 2024 pm 08:31 PM
Through the Go standard library database/sql package, you can connect to remote databases such as MySQL, PostgreSQL or SQLite: create a connection string containing database connection information. Use the sql.Open() function to open a database connection. Perform database operations such as SQL queries and insert operations. Use defer to close the database connection to release resources.
How to save JSON data to database in Golang?
Jun 06, 2024 am 11:24 AM
JSON data can be saved into a MySQL database by using the gjson library or the json.Unmarshal function. The gjson library provides convenience methods to parse JSON fields, and the json.Unmarshal function requires a target type pointer to unmarshal JSON data. Both methods require preparing SQL statements and performing insert operations to persist the data into the database.
