According to AWS pages, if a file size is big enough it will automatically use multi part uploads so I can run this command

aws s3 cp large_test_file s3://DOC-EXAMPLE-BUCKET/

and the upload should be multipart.

However, I am uploading a 1gb file and it seems to be uploading it as a normal file.

Furthermore, my bucket policy has no permissions for multipart list or upload (just put object) so I don't understand how that is working.

Would like some clarity on this if it is

• Indeed using multipart upload (without informing me)
• How is it able to do so without me granting it permissions?

CodePudding user response：

The documentation for Multipart Uploads mentions this near the section on permissions:

Create Multipart Upload

You must be allowed to perform the s3:PutObject action on an object to create multipart upload.

The bucket owner can allow other principals to perform the s3:PutObject action.

In other words, the PutObject permission allows PutObject, but also CreateMultipartUpload and related calls necessary to perform a multipart upload.