Adding a Volume to an Ubuntu EC2 Instance

AWS / 2 min read

Some quick notes on adding a storage volume to an EC2 instance.

A short while ago I put together a m4.2xlarge EC2 instance. My initial thoughts were that the CPU (8 virtual CPUs), RAM (32 GiB) and storage space (16 GiB) would be more than enough for my requirements. I was correct about the first two, but ran out of storage pretty quickly. I had two options: rebuild from scratch with more storage space or simply add another volume. In light of all the provisioning that I’d done, the latter option was definitely more appealing.

Adding a New Volume

  1. In the EC2 Management Console click on Volumes in menu at left.
  2. Press the Create Volume button.
  3. Choose the size of the volume and the Availability Zone. The latter must be the same as that of the EC2 instance to which the volume will be attached.
Adding a new volume in the AWS console.
  1. Press the Create button.
  2. After a short delay the new volume will appear in the list of available volumes. (I have found that I occasionally need to refesh the page to get the new volume to show up!)
  3. Select the newly created volume and press the Actions button. Choose Attach Volume.
  4. Click the Instance field. It should present you with a list of running instances, from which you can select the appropriate option. If not, manually fill in the ID of the EC2 instance you want. Also specify a location in /dev/ where you want it to appear (something in the range /dev/sdf to /dev/sdp should work), although this will probably be filled with a default value, which is perfectly good!

Mounting the New Volume

  1. Connect to the EC2 instance using SSH.
  2. Check for the new volume. Note that it will probably have have a different device name from what you specified above.
sudo lsblk

Suppose that the new volume shows up at /dev/xvdf.

What you do next depends on how you want to use the partition.

Swap Partition

First set up a swap area on the new partition.

sudo mkswap /dev/xvdf

Then enable the partition for swapping.

sudo swapon /dev/xvdf

File Partition

Create a file system on the raw device.

sudo mkfs -t ext4 /dev/xvdf

Go ahead and mount /dev/xvdf at a suitable location in your file hierarchy.