# How Amazon SageMaker Processing Configures Input and Output For Your Processing Container
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When you create a processing job using the `CreateProcessingJob` operation, you can specify multiple `ProcessingInput` and `ProcessingOutput`. values. 

You use the `ProcessingInput` parameter to specify an Amazon Simple Storage Service (Amazon S3) URI to download data from, and a path in your processing container to download the data to. The `ProcessingOutput` parameter configures a path in your processing container from which to upload data, and where in Amazon S3 to upload that data to. For both `ProcessingInput` and `ProcessingOutput`, the path in the processing container must begin with `/opt/ml/processing/ `.

For example, you might create a processing job with one `ProcessingInput` parameter that downloads data from `s3://your-data-bucket/path/to/input/csv/data` into `/opt/ml/processing/csv` in your processing container, and a `ProcessingOutput` parameter that uploads data from `/opt/ml/processing/processed_csv` to `s3://your-data-bucket/path/to/output/csv/data`. Your processing job would read the input data, and write output data to `/opt/ml/processing/processed_csv`. Then it uploads the data written to this path to the specified Amazon S3 output location. 

**Important**  
Symbolic links (symlinks) can not be used to upload output data to Amazon S3. Symlinks are not followed when uploading output data.