By default, if you provision and attach additional EBS volumes for an EC2 instance, they don’t get mounted by default.
The boot EBS is usually /dev/xvda1. Each additional EBS volume should be /dev/xvdb and so on.
First format the new volume:
sudo mkfs -t ext4 /dev/xvdb
Make a mount mount directory like /data, then mount it with:
sudo mount /dev/xvdb /data
Now you should see the new volume available:
$ df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 3.9G 0 3.9G 0% /dev tmpfs 3.9G 0 3.9G 0% /dev/shm tmpfs 3.9G 432K 3.9G 1% /run tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup /dev/xvda1 20G 8.8G 12G 44% / tmpfs 798M 0 798M 0% /run/user/1000 /dev/xvdb 7.8G 36M 7.3G 1% /data
Add a line to /etc/fstab to mount on startup:
/dev/xvdb /data ext4 defaults,nofail 0 2
These steps are from multiple places, mainly answers to this question.