Attaching and mounting existing EBS volume to EC2 instance filesystem issue

I had some unknown issue with my old EC2 instance so that I can't ssh into it anymore. Therefore I created a new EBS volume from a snapshot of the old volume and tried to attach and mount it to the new instance. Here is what I did:

1. Created a new volume from snapshot of the old one.


2. Created a new EC2 instance and attached the volume to it as /dev/xvdf (or /dev/sdf)


3. 
   

   SSHed into the instance and attempted to mount the old volume with:

   
   

   $ sudo mkdir -m 000 /vol $ sudo mount /dev/xvdf /vol

   
   

And the output was:

mount: block device /dev/xvdf is write-protected, mounting read-only
mount: you must specify the filesystem type

Now, I know I should specify the filesytem as ext4 but since the volume contains a lot of important data, I cannot format it through $ sudo mkfs -t ext4 /dev/xvdf. Still, I know of no other way of preserving the data and specifying the filesystem at the same time. I've searched a lot about it and I'm currently at a loss.

By the way, the mounting as 'read-only' also worries me but I haven't look into it yet since I can't mount the volume at all.

Thanks in advance!