When you run a backup job with the file indexing option enabled, Veeam Backup & Replication indexes the VM file system, collects indexing data and writes it to the GuestIndexData.zip file. The GuestIndexData.zip file is first stored in a temporary folder on the Veeam backup server.
As soon as the backup job completes, Veeam Backup & Replication notifies the local Veeam Backup Catalog service, and the service saves indexing data in the Veeam Backup Catalog folder on the Veeam backup server. During the next catalog replication session started on Veeam Backup Enterprise Manager, indexing data from the Veeam backup server is replicated to the Veeam Backup Catalog on Veeam Backup Enterprise Manager server. By federating indexing data from all connected Veeam backup servers, the Veeam Backup Catalog service on Veeam Backup Enterprise Manager creates a global catalog for the whole backup infrastructure.
