When uploading a very large file to AWS S3 (> 100GB), you may wanna split the file and then upload its parts using the Multipart file Upload tool provided by AWS.

That way, if you lose connection for a reason, you’ll be able to resume the upload with no problems. Also, using the prefix --content-md5, you can check the content of the uploaded file and compare it with your local file.

You can check the Github Repository here.

Steps to use this script

  1. Create a multipart upload using the AWS S3 API
    1. Example: aws s3api create-multipart-upload --bucket my-bucket --key 'multipart-1'
    2. Please, take notes of the upload_id and key values; you’ll need them.
  2. Clone this repo
  3. Set permissions: chmod +x multipart.file-upload-s3.sh
  4. Edit multipart.file-upload-s3.sh with your requirements - See variables below for more information.
    1. Change bucket, profile, upload_id and key.
  5. Create the logs directory: cd awsS3-multipart-upload-script && mkdir logs
  6. Run: ./multipart.file-upload-s3.sh
  7. Check AWS documentation for next step. You’ll have to run the complete-multipart-upload command.

The script will start reading your /home/lucas/aws-upload-test/files/x directory for files, will take the MD5 checksum of them and parse it to the S3 API as the --content-md5 parameter, and then it will start uploading each file to the specified bucket. The outputs will be sent to a log file. Make sure to save that log file, you’ll need the ETag output later on.

An example of the output of the script:

{ "ETag": ""e868e0f4719e394144ef36531ee6824c"" }

The script will send the output to another file and format it to be compatible with the AWS requirements for the complete-multipart-upload command.

AWS complete-multipart-upload output example:

{ "Parts": 
		{ "ETag": "e868e0f4719e394144ef36531ee6824c", "PartNumber": 1 }, 
		{ "ETag": "6bb2b12753d66fe86da4998aa33fffb0", "PartNumber": 2 }, 
		{ "ETag": "d0a0112e841abec9c9ec83406f0159c8", "PartNumber": 3 } 

More information about the split command for Linux here.


  • bucket = Your S3 bucket name.
  • profile = Your AWS profile (i.e. aws configure --profile tests).
  • upload_id = Your upload_id, retrievable when executing create-multipart-upload.
  • /home/lucas/aws-upload-test/files/x = The directory in your HD that contains the splitted files.
  • key = Object key for which the multipart upload has been initiated.