Back Up Cluster Metadata

This procedure shuts down the mongod instance of aconfig server in order to create abackup of a sharded cluster’smetadata. The cluster’s config servers store all of the cluster’smetadata, most importantly the mapping from chunks toshards.

When you perform this procedure, the cluster remains operational[1].

  • Disable the cluster balancer process temporarily. SeeDisable the Balancer for more information.
  • Shut down one of the config databases.
  • Create a full copy of the data files (i.e. the path specified bythe dbPath option for the config instance.)
  • Restart the original configuration server.
  • Re-enable the balancer to allow the cluster to resume normalbalancing operations. See theDisable the Balancer section for moreinformation on managing the balancer process.

See also

MongoDB Backup Methods.

[1]While one of the three config servers is unavailable,the cluster cannot split any chunks nor can it migrate chunksbetween shards. Your application will be able to write data to thecluster. See Config Servers for more information.