If you need to add some more space to an instance running on EC2, and that instance is running the latest LTS version of UBUNTU. It is fairly easy to do.

First, create an instance in the management console of AWS and attach it to your instance. Note - you need to create the EBS in the same AZ that your instance is running. After you EBS has been attached, you need to see where AWS mounted your image on your instance. Login to your instance and check it out

ubuntu@ip-1-1-1-93:/vol$ sudo fdisk -l

Disk /dev/xvda: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders, total 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Device Boot Start End Blocks Id System
/dev/xvda1 * 16065 16771859 8377897+ 83 Linux

Disk /dev/xvdf: 268.4 GB, 268435456000 bytes
255 heads, 63 sectors/track, 32635 cylinders, total 524288000 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/xvdf doesn't contain a valid partition table

As you can see from the above output, I created a new 250 GB EBS and AWS has attached it at /dev/xvdf. Now that it is attached, you need to format it. I recommend using ext4 file extension, but what you use may depend on performance requirements.

Assuming you are going with ext4, you need to report the disk using the following command:

sudo mkfs.ext4 /dev/xvdf

Reformatting should only take a few minutes, depending on the size of your EBS. Once it is reformatted, you need to update the /etc/fstab file to tell UBUNTU about your new disk and where it is mounted.

sudo mkdir -m 000 /vol
echo "/dev/xvdf /vol auto noatime 0 0" | sudo tee -a /etc/fstab

Save fstab and now you should be able to mount your disk successfully

sudo mount /vol

Finally, confirm your new EBS is working properly.

ubuntu@ip-1-1-1-93:/vol$ df --si
Filesystem Size Used Avail Use% Mounted on
udev 4.2G 13k 4.2G 1% /dev
tmpfs 838M 357k 837M 1% /run
/dev/xvda1 8.4G 1.2G 6.8G 15% /
none 4.1k 0 4.1k 0% /sys/fs/cgroup
none 5.3M 0 5.3M 0% /run/lock
none 4.2G 0 4.2G 0% /run/shm
none 105M 0 105M 0% /run/user
/dev/xvdf 265G 4.0G 247G 2% /vol

Done