aws s3 mb Failed – BucketAlreadyExists ( AWSCLI )

Error Message

make_bucket failed: s3://proxystats An error occurred (BucketAlreadyExists) when calling the CreateBucket operation: The requested bucket name is not available. The bucket namespace is shared by all users of the system. Please select a different name and try again.

Why this happened?

It is because S3 bucket name is global namespace in S3 shared by other S3 user as well. Therefore, it has be unique in global level.