Managing the repository (where the data is stored) is the most crucial part in Elasticsearch backup management. Due to its native distributed architecture, the snapshot and the restore are designed in a cluster style.
During a snapshot, the shards are copied to the defined repository. If this repository is local to the nodes, then the backup data is spread across all the nodes. For this reason, it's necessary to have shared repository storage if you have a multinode cluster.
A common approach is to use an NFS, as it's very easy to set up and it's a very quick solution (additionally, standard Windows Samba shares can be used.)
