robustness

问题 I am building a server app that copies files using System.IO.File.Copy(...) function. My files can be rather large, therefore, it has a fair chance that if the machine crashes, it happens during copying. After restarting the service, I should be able to pick up the copy tasks and continue. How can I detect if a copy has been successfully completed or interrupted by server crash? My current plan is to copy the files to a temporary name and once copying completed rename it to the final name.