How to increase EBS volume size

AwsHow-ToBeginner · 4 min read

How to Increase AWS EBS Volume Size Quickly and Safely

To increase an AWS EBS volume size, modify the volume using the AWS Management Console or AWS CLI with the new desired size. After resizing, extend the file system on your instance to use the additional space.

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Syntax

Use the AWS CLI command modify-volume to increase the size of an EBS volume. The key parts are:

--volume-id: The ID of the volume to resize.
--size: The new size in GiB (must be equal or larger than current size).

Example syntax:

bash

aws ec2 modify-volume --volume-id vol-1234567890abcdef0 --size 100

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Example

This example shows how to increase an EBS volume from 50 GiB to 100 GiB using AWS CLI, then extend the file system on a Linux instance.

bash

# Step 1: Modify the volume size
aws ec2 modify-volume --volume-id vol-0abcd1234efgh5678 --size 100

# Step 2: Check modification status
aws ec2 describe-volumes-modifications --volume-ids vol-0abcd1234efgh5678

# Step 3: Connect to your EC2 instance and extend the file system
sudo growpart /dev/xvdf 1
sudo resize2fs /dev/xvdf1

Output

ModifyVolume: volume modification started DescribeVolumesModifications: modification state: optimizing File system resized successfully

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Common Pitfalls

Trying to shrink the volume size is not supported; you can only increase it.
Forgetting to extend the file system after resizing will leave the extra space unusable.
Using the wrong device name when extending the partition or file system can cause errors.
Not waiting for the volume modification to complete before resizing the file system can cause failures.

bash

# Wrong: resizing file system before volume modification completes
sudo resize2fs /dev/xvdf1

# Right: wait for modification, then resize
aws ec2 wait volume-modified --volume-ids vol-0abcd1234efgh5678
sudo resize2fs /dev/xvdf1

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Quick Reference

Step	Command / Action	Notes
1	Modify volume size	aws ec2 modify-volume --volume-id --size
2	Wait for modification	aws ec2 wait volume-modified --volume-ids
3	Extend partition	sudo growpart /dev/
4	Resize file system	sudo resize2fs /dev/ (ext4 example)

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Key Takeaways

You can only increase EBS volume size, not decrease it.

Use AWS CLI or Console to modify the volume size safely.

Always extend the file system after resizing the volume to use new space.

Wait for the volume modification to complete before resizing the file system.

Check your device names carefully when extending partitions and file systems.