Back Up a Sharded Cluster with File System Snapshots使用文件系统快照备份分片群集

Disable the balancer.禁用均衡器。

Connect mongosh to a cluster mongos instance. Use the sh.stopBalancer() method to stop the balancer.将mongosh连接到群集mongos实例。使用shstopBalancer()方法停止均衡器。 If a balancing round is in progress, the operation waits for balancing to complete before stopping the balancer.如果正在进行一轮平衡，操作将等待平衡完成，然后停止均衡器。

use config
sh.stopBalancer()

Starting in MongoDB 4.2, sh.stopBalancer() also disables auto-splitting for the sharded cluster.从MongoDB 4.2开始，sh.stopBalancer()还禁用分片集群的自动拆分。

For more information, see the Disable the Balancer procedure.有关更多信息，请参阅禁用均衡器程序。

If necessary, lock one secondary member of each replica set.如有必要，锁定每个副本集的一个辅助成员。

If your secondary does not have journaling enabled or its journal and data files are on different volumes, you must lock the secondary's mongod instance before capturing a backup.如果辅助服务器未启用日志记录，或者其日志和数据文件位于不同的卷上，则必须在捕获备份之前锁定辅助服务器的mongod实例。

If your secondary has journaling enabled and its journal and data files are on the same volume, you may skip this step.如果辅助设备已启用日志记录，并且其日志和数据文件位于同一卷上，则可以跳过此步骤。

Ensure that the oplog has sufficient capacity to allow these secondaries to catch up to the state of the primaries after finishing the backup procedure. 确保oplog有足够的容量，使这些二级备份在完成备份过程后能够赶上初级备份的状态。See Oplog Size for more information.有关更多信息，请参阅Oplog Size。

use config
db.BackupControl.findAndModify(
   {
     query: { _id: 'BackupControlDocument' },
     update: { $inc: { counter : 1 } },
     new: true,
     upsert: true,
     writeConcern: { w: 'majority', wtimeout: 15000 }
   }
);

The operation should return the modified (or inserted) control document:操作应返回修改（或插入）的控制文件：

{ "_id" : "BackupControlDocument", "counter" : 1 }

Query the shard secondary member for the returned control document. Connect mongosh to the shard secondary to lock and use db.collection.find() to query for the control document:

rs.secondaryOk();
use config;
db.BackupControl.find(
   { "_id" : "BackupControlDocument", "counter" : 1 }
).readConcern('majority');

If the secondary member contains the latest control document, it is safe to lock the member. 如果辅助成员包含最新的控制文档，则可以安全地锁定该成员。Otherwise, wait until the member contains the document or select a different secondary member that contains the latest control document.否则，请等待成员包含该文档，或选择包含最新控制文档的其他辅助成员。

To lock the secondary member, run db.fsyncLock() on the member:要锁定辅助成员，请在该成员上运行db.fsyncLock()：

db.fsyncLock()

use config
db.BackupControl.findAndModify(
   {
     query: { _id: 'BackupControlDocument' },
     update: { $inc: { counter : 1 } },
     new: true,
     upsert: true,
     writeConcern: { w: 'majority', wtimeout: 15000 }
   }
);

The operation should return the modified (or inserted) control document:操作应返回修改（或插入）的控制文件：

{ "_id" : "BackupControlDocument", "counter" : 1 }

Query the CSRS secondary member for the returned control document. Connect mongosh to the CSRS secondary to lock and use db.collection.find() to query for the control document:向CSRS次要成员查询返回的控制文档。将mongosh连接到CSRS secondary以锁定，并使用db.collection.find()查询控制文档：

rs.secondaryOk();
use config;
db.BackupControl.find(
   { "_id" : "BackupControlDocument", "counter" : 1 }
).readConcern('majority');

If the secondary member contains the latest control document, it is safe to lock the member. 如果辅助成员包含最新的控制文档，则可以安全地锁定该成员。Otherwise, wait until the member contains the document or select a different secondary member that contains the latest control document.否则，请等待成员包含该文档，或选择包含最新控制文档的其他辅助成员。

To lock the secondary member, run db.fsyncLock() on the member:要锁定辅助成员，请在该成员上运行db.fsyncLock()：

db.fsyncLock()

Back up one of the config servers.备份其中一个配置服务器。

To create a file-system snapshot of the config server, follow the procedure in Create a Snapshot.要创建配置服务器的文件系统快照，请按照创建快照中的过程操作。

Back up a replica set member for each shard.为每个分片备份一个副本集成员。

If you locked a member of the replica set shards, perform this step against the locked secondary.如果锁定了复制集分片的成员，请对锁定的次分片执行此步骤。

You may back up the shards in parallel. 你可以同时备份分片。For each shard, create a snapshot, using the procedure in Back Up and Restore with Filesystem Snapshots.对于每个分片，使用文件系统快照备份和恢复中的过程创建一个快照。

Unlock all locked replica set members.解锁所有锁定的副本集成员。

If you locked any mongod instances to capture the backup, unlock them.如果您锁定了任何mongod实例以捕获备份，请解锁它们。

To unlock the replica set members, use db.fsyncUnlock() method in mongosh.要解锁副本集成员，请在mongosh中使用db.fsyncUnlock()方法。

db.fsyncUnlock()

Enable the balancer.启用平衡器。

To re-enable to balancer, connect mongosh to a mongos instance and run sh.startBalancer().要重新启用均衡器，请将mongosh连接到mongos实例，然后运行sh.startBalancer()。

sh.startBalancer()

Starting in MongoDB 4.2, sh.startBalancer() also enables auto-splitting for the sharded cluster.从MongoDB 4.2开始，sh.startBalancer()还为分片集群启用自动拆分。