AWS - EBS Attached But Can't Find On Instance

Not sure if it will be the reason in your case, but we found a similar problem while integrating Fedora images in our infrastructure for BitNami Cloud Hosting.

Some kernels use /dev/xvd* instead of /dev/sd*. In your case, if you have attached the volume with device name /dev/sdh it would appear as /dev/xvdh in the machine.

I hope it helps.

When you attach a new EBS volume to an EC2 instance, there is nothing present on the volume, not even filesystem. Hence if you do df -h, it won't show up.

You should use lsblk command to list all the attached disks.

You will have to format it to make it usable. Here is the useful link for that.

Also, @CarlosSM's answer is correct that sometimes the name of the volume is different than what is specified.