mount already mounted or busy
<p>I have an Amazon EC2 instance (Ubuntu 12.04) to which I have attached two 250 GB volumes. Inadvertently, the volumes got unmounted. When I tried mounting them again, with the following command, </p>

<p><code>sudo mount /dev/xvdg /data</code></p>

<p>this is the error I get :</p>

<p><code>mount: /dev/xvdg already mounted or /data busy</code></p>

<p>Then, I tried un-mounting it as follows :
<code>umount /dev/xvdg</code> but it tells me that the volume is not mounted.</p>

<p><code>umount: /dev/xvdg is not mounted (according to mtab)</code></p>

<p>I tried <code>lsof</code> to check for any locks but there weren't any.</p>

<p>The lsblk output is as below :</p>

<p><a href="https://i.stack.imgur.com/UvfuU.png" rel="noreferrer"><img src="https://i.stack.imgur.com/UvfuU.png" alt="enter image description here"></a></p>

<p>Any help will be appreciated. What do I need to do to mount the volumes back without losing the data on them?</p>