Veeam Backup & Replication performs file share backup in the following way:
- When a new backup job session starts, Veeam Backup & Replication assigns a file proxy to enumerate files and folders on the file share and to create a file tree with cyclic redundancy check (CRC) values.
- The file proxy enumerates files and folders on the file share and creates the file tree with CRC values.
- The file proxy transfers the file tree to the cache repository.
- The cache repository saves the file tree.
- When the cache repository receives a new tree structure from the proxy, it compares it with the file tree created during the previous run of the backup session. If any files or folders of the file share have changed since the previous backup session run, the cache repository instructs the file proxy to start reading changed data from the source file share.
- The file proxy reads new data from the file share.
- The file proxy creates data packages. Data packages contain backup data saved as data files (each 64 Mb in size) and metadata files that contain names and versions of backup files and allocation of data in backup files.
- The file proxy sends new data to the target backup repository.