Resizing an EC2 instance volume | Thorn Technologies

Resizing an EC2 instance volume

Expanding Storage on your EC2 instance

For standard (magnetic) volume types

The CloudFormation template install will default to standard magnetic EBS volume type. Magnetic does not support resizing, so you'll have to create a snapshot, create a new volume, and then then remount it.

(1) Stop your EC2 instance

Go to EC2 and select your instance

Go to Actions > Instance State > Stop

In the EC2 instance details, make a note of the Availability zone (you'll need this later)

Also note the Root device mount path. For example, this might be /dev/xvda (you'll need this later too)

(2) Find your instance's EBS volume

A shortcut I like to use is to click on the Root device /dev/xvda link in the EC2 instance details. In the pop-up, click on the link next to EBS ID.

(3) Go to Actions > Create Snapshot. This creates a backup.

For the snapshot description, type in SFTP Gateway snapshot

Add a tag.

  • KeyName
  • ValueSFTP Gateway snapshot

Click Create Snapshot

Click the link provided to navigate to your snapshot.

Wait a few moments for the snapshot to create. Use the refresh button near the top right of the screen.

(4) Create a volume from the snapshot

Go to Actions > Create Volume

Select General Purpose SSD (GP2) as the Volume Type

Change the volume size

Change the Availability Zone to match your EC2 instance's AZ

Add a Tag so you can easily identify the volume later

Click Create Volume

Click the link to navigate to your Volume Id.

(5) Unmount the magnetic volume

Find the original magnetic EBS volume. You can go back to your EC2 instance, and click on /dev/xvda again.

Go to Actions > Detach Volume

(6) Mount the resized GP2 volume

Find the resized GP2 EBS volume

Go to Actions > Attach volume

Select the SFTP Gateway instance from the drop down menu

For Device, enter the root device path (i.e. /dev/xvda, or whatever you noted earlier)

Click Attach

(7) Start the EC2 instance

Run the following command to make sure you're utilizing the new volume size

df -h

For GP2 volume types

(Note: most CloudFormation template installations default to standard magnetic EBS volume type. Please refer to the section above for resizing instructions)

The best approach would be to resize the EC2 instance volume. AWS provides instructions on how to do so here:

This document can be pretty intimidating. But here's a condensed version:

  • First, stop your EC2 instance.
  • Go to EC2 > Volumes and find your instance's volume.
  • Go to Actions > Create Snapshot. This creates a backup.
  • Go to Actions > Modify Volume, and increase the storage size. For now, specify 64 GB.
  • It'll take a while for the volume resize operation to complete. But under your volume's details, look for the "state". Once it is "optimizing", you can proceed.
  • Run the following (note the space between xvda and 1): sudo growpart /dev/xvda 1

  • Run the following: sudo resize2fs /dev/xvda1

Here's what's going on. Increasing the EC2 volume is a 3-step process. Imagine you're inflating 3 balloons nested inside each other. But you have to inflate the outer one first to make room for the inner ones.

  1. The outermost layer is the EBS volume. You increased this via the "Modify Volume" step in the AWS console.
  2. The middle layer is the partition. You increased this using growpart. You can use lsblk to verify that you're using the full 64 GB volume.
  3. The inner layer is the file system. You increased this using resize2fs. You use df -h to verify that you're using the full partition.

The documentation has a lot of explanation and tangents for edge cases that you can refer to. But the actual process is just Modify Volume in the AWS console, and two commands: growpart and resize2fs.