Restore a Replica Set from MongoDB Backups从MongoDB备份恢复副本集

Obtain backup MongoDB Database files.获取MongoDB数据库备份文件。

The backup files may come from a file system snapshot. The MongoDB Cloud Manager produces MongoDB database files for stored snapshots and point in time snapshots. 备份文件可能来自文件系统快照。MongoDB Cloud Manager为存储的快照和时间点快照生成MongoDB数据库文件。For Ops Manager, an on-premise solution available in MongoDB Enterprise Advanced, see also the Ops Manager Backup overview.对于Ops Manager，MongoDB Enterprise Advanced中提供的内部部署解决方案，另请参阅Ops Manager备份概述。

Considerations for Encrypted Storage Engines加密存储引擎的注意事项

For encrypted storage engines that use AES256-GCM encryption mode, AES256-GCM requires that every process use a unique counter block value with the key.对于使用AES256-GCM加密模式的加密存储引擎，AES256-GCM要求每个进程使用唯一的计数器块值和键。For encrypted storage engine configured with AES256-GCM cipher: 对于配置有AES256-GCM密码的加密存储引擎：

Restoring from Hot Backup从热备份恢复

Starting in 4.2, if you restore from files taken via "hot" backup (i.e. the mongod is running), MongoDB can detect "dirty" keys on startup and automatically rollover the database key to avoid IV (Initialization Vector) reuse.从4.2开始，如果你从通过“热”备份（即mongod正在运行）获取的文件中恢复，MongoDB可以在启动时检测到“脏”键，并自动滚动数据库键，以避免IV（初始化向量）重用。

Restoring from Cold Backup从冷备份恢复

However, if you restore from files taken via "cold" backup (i.e. the mongod is not running), MongoDB cannot detect "dirty" keys on startup, and reuse of IV voids confidentiality and integrity guarantees.然而，如果您从通过“冷”备份获取的文件中恢复（即mongod没有运行），MongoDB在启动时无法检测到“脏”键，并且IV的重用将失去机密性和完整性保证。

Starting in 4.2, to avoid the reuse of the keys after restoring from a cold filesystem snapshot, MongoDB adds a new command-line option --eseDatabaseKeyRollover. 从4.2开始，为了避免从冷文件系统快照恢复后重用键，MongoDB添加了一个新的命令行选项--eseDatabaseKeyRollover。When started with the --eseDatabaseKeyRollover option, the mongod instance rolls over the database keys configured with AES256-GCM cipher and exits.当使用--eseDatabaseKeyRollover选项启动时，mongod实例会滚动使用AES256-GCM密码配置的数据库键并退出。

Tip

• In general, if using filesystem based backups for MongoDB Enterprise 4.2+, use the "hot" backup feature, if possible.通常，如果MongoDB Enterprise 4.2+使用基于文件系统的备份，请尽可能使用“热”备份功能。
• For MongoDB Enterprise versions 4.0 and earlier, if you use AES256-GCM encryption mode, do not make copies of your data files or restore from filesystem snapshots ("hot" or "cold").对于MongoDB Enterprise 4.0及更早版本，如果使用AES256-GCM加密模式，请不要复制数据文件或从文件系统快照（“热”或“冷”）进行恢复。

Drop the local database if it exists in the backup.如果备份中存在local数据库，请删除该数据库。

If you are restoring from a filesystem backup (or any backup with the local database), drop the local database.如果要从文件系统备份（或使用local数据库的任何备份）进行恢复，请删除local数据库。

mongod --dbpath /data/db

use local
db.dropDatabase()

Start a new single-node replica set.启动新的单节点复制副本集。

Start a mongod instance as a new single-node replica set. 将mongod实例作为新的单节点副本集启动。Specify the path to the backup data files with --dbpath option and the replica set name with the --replSet option. 使用--dbpath选项指定备份数据文件的路径，使用--replSet选项指定副本集名称。For config server replica set (CSRS), include the --configsvr option. Include any other options as appropriate for your deployment.对于配置服务器副本集（CSRS），包括--configsvr选项。包括适用于您的部署的任何其他选项。

mongod --dbpath /data/db --replSet <replName>

Connect mongosh to the mongod instance.将mongosh连接到mongod实例。

From the same machine where one of the mongod is running (in this tutorial, mongodb0.example.net), start mongosh. 在运行其中一个mongod的同一台机器上（在本教程中，mongodb0.example.net），启动mongosh。To connect to the mongod listening to localhost on the default port of 27017, simply issue:要连接到默认端口27017上监听localhost的mongod，只需发出：

mongosh

Depending on your path, you may need to specify the path to the mongosh binary.根据您的路径，您可能需要指定mongosh二进制文件的路径。

If your mongod is not running on the default port, specify the --port option for mongosh.如果您的mongod没有在默认端口上运行，请为mongosh指定--port选项。

Initiate the new replica set.启动新的复制副本集。

Use rs.initiate() on one and only one member of the replica set:在副本集中的一个且仅一个成员上使用rs.initiate()：

rs.initiate( {
   _id : <replName>,
   members: [ { _id : 0, host : <host:port> } ]
})

MongoDB initiates a set that consists of the current member and that uses the default replica set configuration.MongoDB启动一个由当前成员组成的集合，该集合使用默认的副本集配置。