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The gateway implements the S3 operations that storage tooling actually uses. This page is the honest list: what works, what returns an error code instead of pretending, and the places where Tapedrive’s model shows through the S3 API.

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Supported operations

Recognized-but-unsupported S3 subresources (versioning, ACLs, and similar) return 501. On supported operations the gateway reads only the SigV4 headers (x-amz-date, x-amz-content-sha256, and x-amz-decoded-content-length for chunked uploads) plus Content-Type on PutObject; every other request header, including x-amz-meta-*, storage-class, and encryption headers, is ignored rather than rejected.

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ETags are on-chain commitments

ETag values here are the object’s on-chain commitment, and that’s the divergence your tooling is most likely to notice. The value is deterministic, identical across every gateway and every operation, and a valid opaque ETag, which is all S3 itself guarantees for multipart uploads. It is not an MD5 of your file. A client that compares ETag against a local MD5 will report mismatches that don’t indicate corruption. Change-detection tooling that treats ETags as opaque (rclone’s default behavior) works correctly.
If your client warns on ETag mismatch, disable its MD5-checksum verification. The data is verified far more strongly than MD5 on every read (how reads verify).

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Signing

The gateway accepts SigV4 via headers or presigned URLs. Signed payloads are hash-verified against x-amz-content-sha256, and presigned-URL expiry is enforced. Anonymous GET, HEAD, and LIST are allowed. SigV2 is not supported; a SigV2 request is treated as unsigned.

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Semantics differences

Three behaviors come from the object layer underneath. Know them before you build on it:
  • Overwrite is last-write-wins. Writing to an existing key creates a new track under the same name; there is no versioning (objects).
  • Deletes are real and idempotent. Deleted capacity returns to the tape.
  • Buckets can expire. An object lives as long as its bucket’s tape. AWS has no concept for this, so your tooling won’t warn you: watch tape expiry and extend in time (tapes).