Storage Backends

What this section covers

Tutorials here are organized by backend type: how to prepare the external service, create the storage policy, configure policy group rules, move users or teams over, and validate before going live. The two-layer concept of storage policies and policy groups itself lives in Storage Policies and Policy Groups.

Choosing a Backend

Backend	Best for	Tutorial
Local Disk	Single machine, NAS, small teams, minimal dependencies	Local Disk
S3 / MinIO / R2	Object storage, large files, external buckets, cloud storage	S3 / MinIO / R2
Azure Blob Storage	Azure Storage accounts, Blob containers, Azure-managed object storage	Azure Blob Storage
Tencent Cloud COS	Tencent Cloud object storage, COS CI, per-policy native processing	Tencent Cloud COS
OneDrive	Microsoft 365, OneDrive, SharePoint / group drives, Microsoft Graph authorization	OneDrive
SFTP	SSH/SFTP file servers, NAS, traditional server directories, server-side streaming	SFTP
Remote Node	Control plane on the primary, real objects written to another AsterDrive	Follower Node Storage Policy

For multi-Primary (cluster profile) deployments, the default policy must be reachable by every Primary, and local cannot be the default policy; see Storage Policies and Policy Groups.

For each backend’s direct-upload capability, capacity observation, native processing, and credentials at rest — plus how to choose between relay_stream and presigned — see the Storage Capability Matrix.

Shared Onboarding Flow

Do Not Switch Production Traffic Yet

For a new backend, create a separate new policy; do not edit the old policy that is in use.

Recommended approach:

1. Create the backend policy
2. Create a test policy group
3. Bind a test user or test team
4. Run upload, download, share, delete, and restore end to end
5. Only then migrate real users or teams to the new policy group

Do not edit the real landing location of a policy that already has files

The local directory, S3 bucket / endpoint / prefix, Azure Blob endpoint / container / base path, OneDrive drive / root item / site / group targeting fields, SFTP endpoint / base path, and the bound remote node all decide where old files live. Change them in place and old files may become unfindable. For the correct move procedure, see Storage Policies and Policy Groups.