Question

I have a windows service (C# .Net 3.5) that grabs data from a network share and does a copy to the host of the service.

The size of the data copied ranges from 50KB to 750MB, and the number of files copied varies. In perhaps 20% of the copies I am getting System.IO.IOException: The specified network name is no longer available.

My google-fu is failing to turn up an answer as to what might cause this during a File.Copy. Has anyone seen/solved this before?

Here is the recursive method that does the copy. The exception occurs on line File.Copy(fromFile, toFile, overwrite);

private static int RecursiveCopyDirectory(string from, string to, bool merge, bool overwrite, int depth)
    {
        depth++;

        if (!from.EndsWith(Path.DirectorySeparatorChar.ToString()))
        {
            to += Path.DirectorySeparatorChar;
        }
        if (!to.EndsWith(Path.DirectorySeparatorChar.ToString()))
        {
            to += Path.DirectorySeparatorChar;
        }

        System.Diagnostics.Debug.WriteLine(string.Format("RecursiveDirectoryCopy( {0}, {1}, {2} )", from, to, merge));
        if (Directory.Exists(to))
        {
            if (!merge)
            {
                return (int)EventEnum.FileSystemError_DirectoryAlreadyExists;
            }
        }
        else
        {
            Directory.CreateDirectory(to);
        }

        string[] directories = Directory.GetDirectories(from);

        foreach (string fromDirectory in directories)
        {
            string [] fromDirectoryComponents = fromDirectory.Split(Path.DirectorySeparatorChar);
            string toDirectory = to + fromDirectoryComponents[fromDirectoryComponents.Length - 1];
            RecursiveCopyDirectory(fromDirectory, toDirectory, merge, overwrite, depth);
        }

        string[] files = Directory.GetFiles(from);

        foreach (string fromFile in files)
        {
            string fileName = Path.GetFileName(fromFile);
            //System.Diagnostics.Debug.WriteLine(string.Format("Name: {0}", to + fileName));    
            string toFile = to + fileName;

            File.Copy(fromFile, toFile, overwrite);
        }

        return (int)EventEnum.GeneralSuccess;
    }

Answer 1

It turns out that the customer that was using this software was running two instances of it simultaneously, against the same data set. Once the redundant instance was stopped it resolved the error. Thanks everyone who answered.