Uploading Large Archives in Parts (Multipart Upload) - Amazon S3 Glacier
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This page is only for existing customers of the S3 Glacier service using Vaults and the original REST API from 2012.

If you're looking for archival storage solutions we suggest using the S3 Glacier storage classes in Amazon S3, S3 Glacier Instant Retrieval, S3 Glacier Flexible Retrieval, and S3 Glacier Deep Archive. To learn more about these storage options, see S3 Glacier storage classes and Long-term data storage using S3 Glacier storage classes in the Amazon S3 User Guide. These storage classes use the Amazon S3 API, are available in all regions, and can be managed within the Amazon S3 console. They offer features like Storage Cost Analysis, Storage Lens, advanced optional encryption features, and more.

Uploading Large Archives in Parts (Multipart Upload)

Multipart Upload Process

As described in Uploading an Archive in Amazon S3 Glacier, we encourage Amazon S3 Glacier (S3 Glacier) customers to use Multipart Upload to upload archives greater than 100 mebibytes (MiB).

  1. Initiate Multipart Upload

    When you send a request to initiate a multipart upload, S3 Glacier returns a multipart upload ID, which is a unique identifier for your multipart upload. Any subsequent multipart upload operations require this ID. This ID doesn't expire for at least 24 hours after S3 Glacier completes the job.

    In your request to start a multipart upload, specify the part size in number of bytes. Each part you upload, except the last part, must be this size.


    You don't need to know the overall archive size when using multipart uploads. This means that you can use multipart uploads in cases where you don't know the archive size when you start uploading the archive. You only need to decide the part size at the time you start the multipart upload.

    In the initiate multipart upload request, you can also provide an optional archive description.

  2. Upload Parts

    For each part upload request, you must include the multipart upload ID you obtained in step 1. In the request, you must also specify the content range, in bytes, identifying the position of the part in the final archive. S3 Glacier later uses the content range information to assemble the archive in proper sequence. Because you provide the content range for each part that you upload, it determines the part's position in the final assembly of the archive, and therefore you can upload parts in any order. You can also upload parts in parallel. If you upload a new part using the same content range as a previously uploaded part, the previously uploaded part is overwritten.

  3. Complete (or stop) Multipart Upload

    After uploading all the archive parts, you use the complete operation. Again, you must specify the upload ID in your request. S3 Glacier creates an archive by concatenating parts in ascending order based on the content range you provided. S3 Glacier response to a Complete Multipart Upload request includes an archive ID for the newly created archive. If you provided an optional archive description in the Initiate Multipart Upload request, S3 Glacier associates it with the assembled archive. After you successfully complete a multipart upload, you cannot refer to the multipart upload ID. That means you cannot access parts associated with the multipart upload ID.

    If you stop a multipart upload, you cannot upload any more parts using that multipart upload ID. All storage consumed by any parts associated with the stopped multipart upload is freed. If any part uploads were in-progress, they can still succeed or fail even after stopped.

Additional Multipart Upload Operations

Amazon S3 Glacier (S3 Glacier) provides the following additional multipart upload API calls.

  • List Parts—Using this operation, you can list the parts of a specific multipart upload. It returns information about the parts that you have uploaded for a multipart upload. For each list parts request, S3 Glacier returns information for up to 1,000 parts. If there are more parts to list for the multipart upload, the result is paginated and a marker is returned in the response at which to continue the list. You need to send additional requests to retrieve subsequent parts. Note that the returned list of parts doesn't include parts that haven't completed uploading.

  • List Multipart Uploads—Using this operation, you can obtain a list of multipart uploads in progress. An in-progress multipart upload is an upload that you have initiated, but have not yet completed or stopped. For each list multipart uploads request, S3 Glacier returns up to 1,000 multipart uploads. If there are more multipart uploads to list, then the result is paginated and a marker is returned in the response at which to continue the list. You need to send additional requests to retrieve the remaining multipart uploads.

Quick Facts

The following table provides multipart upload core specifications.

Item Specification
Maximum archive size 10,000 x 4 gibibytes (GiB)
Maximum number of parts per upload 10,000
Part size

1 MiB to 4 GiB, last part can be < 1 MiB. You specify the size value in bytes.

The part size must be a mebibyte (1024 kibibytes [KiB]) multiplied by a power of 2. For example, 1048576 (1 MiB), 2097152 (2 MiB), 4194304 (4 MiB), 8388608 (8 MiB).

Maximum number of parts returned for a list parts request 1,000
Maximum number of multipart uploads returned in a list multipart uploads request 1,000