The following assumes you have created a volume in AWS Management Console and attached it to your instance as /dev/sdh.
A brand new volume is unformatted block storage. It shows up as another device, but doesn’t contain a filesystem. (An EBS volume that previously had a filesystem created on it won’t be mounted either by the attachment process).
You can verify that your instance can see the EBS volume by running the following command on the instance:
You’ll see an entry for sdh. At this point, you should create a filesystem and mount it manually. You could create an EXT3 filesystem on the device and then mount it on ‘/mnt/ebs’ with the following commands, (run as root):
mke2fs -F -j /dev/sdh
mount /dev/sdh /mnt/ebs