Does AWS Datasync fail if the file is modified at the same time it is being transferred from source to destination?

Please refer to this documentation regarding Open and Locked files:

Open and locked files

• Keep in mind the following when trying to transfer files that are open (in use) or locked:

• In general, DataSync can transfer open files without any limitations.

• If a file is open and being written to during a transfer, DataSync can detect this kind of inconsistency during the transfer task's verification phase. To get the latest version of the file, you must run the task again.

• If a file is locked and the server prevents DataSync from opening it, DataSync skips the file during the transfer and logs an error.

• DataSync can't lock or unlock files.

If files are modified during a DataSync task, the task will complete and end with failures indicating verification errors. DataSync task verification options validate the data on the destination matches the source [1]. You can rerun the DataSync task with the task option Transfer only data that has changed [2] to compare the source and destination data set and transfer files that do not match. The next hourly scheduled task will also prepare and transfer files that do not match.

[1] https://docs.aws.amazon.com/datasync/latest/userguide/configure-data-verification-options.html

[2] https://docs.aws.amazon.com/datasync/latest/userguide/configure-metadata.html