Bucket requirements for data transfers

Buckets in Nebius AI Cloud and other S3-compatible storage services can be sources and destinations for a data transfer. Additionally, Azure Blob Storage containers are supported as sources. In every data transfer, either the source, the destination or both must be Nebius AI Cloud buckets.

Supported providers and transfer directions

The table below lists all supported transfer directions:

From	To
Nebius AI Cloud	Nebius AI Cloud
Nebius AI Cloud	S3-compatible storage service
Azure Blob Storage	Nebius AI Cloud
S3-compatible storage service	Nebius AI Cloud

If data is transferred from another S3-compatible storage service, verify the consistency of object metadata before starting the transfer. Object Storage relies on the source service to assign accurate timestamps of last modification. If the service sets timestamps incorrectly—for example, to dates in the past during object creation—such objects may be skipped during synchronization, even if they are new or updated.

Versioned buckets as sources

You can transfer data from versioned buckets. For versioned buckets, only the current object version is transferred.

Access to buckets

When you create a data transfer, you provide credentials that Object Storage uses to access the buckets. These credentials belong to accounts in storage services, such as service accounts in Nebius AI Cloud. The accounts perform actions on buckets and objects during the data transfer, so these accounts must have sufficient permissions to perform these actions.

For more information, see Access to buckets for data transfers.