title: SQL database backup query is giving error
body: <p>I wanted to take a backup of the database in SQL Server 2008 R2 through a query. I implemented this query</p>
  
  <pre><code>BACKUP DATABASE Test TO DISK='D:\bakup.bak'
  </code></pre>
  
  <p>But I get an error</p>
  
  <blockquote>
    <p>Msg 3013, Level 16, State 1, Line 1<br>
    Cannot open backup device 'D:\bakup.bak'. Operating system error 21 (The device is not ready.).<br>
    BACKUP DATABASE is terminating abnormally.</p>
  </blockquote>
  
  <p>I dont know why, please help</p>