Have you had a look at MSDN?
https://msdn.microsoft.com/en-us/library/aa337267.aspx A Windows read or write request has failed. The error code that is returned by Windows and the corresponding text are inserted into the message. In the read case, SQL Server will have already retried the read request four times. This error is often the result of a hardware error, but may be caused by the device driver. For more information about error 823, see
http://support.microsoft.com/kb/828339. For more information about I/O errors, see Microsoft SQL Server I/O Basics, Chapter 2.