Amazon EBS (Elastic Block Store) is a scalable, high-performance block-storage service designed for Amazon EC2.
- It can be used to create storage volumes and attach them to EC2 instances.
- All EBS volume types offer durable snapshot capabilities and are designed for 99.999% availability.
EBS' elastic volumes feature allows you to increase volume size while the volume is still in use, making the resizing process easier and faster. It also provides the option to completely change the volume type and adjust its performance - also without downtime.
In an Amazon-Linux system, you can read some information on the EBS volume with the following command:
sudo gdisk -l /dev/xvda
In Linux systems, you can use the following command to display disk usage on the file system:
df -h
It's recommended that you create a snapshot back-up before modifying the volume, in case you need to roll back changes.
From the EC2 left-hand pane:
Snapshots -> Create snapshot
Resource type: Volume
Volume ID: <id-of-EC2-volume>
Description: ex: Wazuh-Manager Snapshot
Click Create snapshot.
It will take some minutes for the volume to be created.
You can check progress in the Snapshot status column.
From the EC2 left-hand pane, click on Volumes.
Check the box for the volume you'd like to modify.
Select any changes you'd like to apply to the EBS volume.
Click on Modify, then click on Modify again to confirm.
In order to finish increasing the size of the volume, you'll need to extend the file system after modifying the volume. The volume will first need to enter the optimizing state. In the EC2 volume's page, the Volume state should read In-use before proceeding.
Connect to your instance, and use the following command:
sudo lsblk
If you look in the output's TYPE column, you'll see the size of the full disk, and the size of the partition. The partition has the old size before you modified the volume for more space. So now you'll extend the partition to allow access to the full disk space that you're paying AWS for!
sudo growpart /dev/xvda 1
Check that the partition was extended:
lsblk
View the file system data with this Linux command:
df -hT
The output should display the Filesystem, Type, Size, Used, Avail, Use%, Mounted on.
The most relevant of these is the Filesystem, Type, and Mount point. In this example, the xvda1 filesystem's Type is xfs, which allows me to use the xfs_growfs command on the / Mount point.
Use the xfs_growfs command to specify the mount point of your desired filesystem, aka xvda1:
sudo xfs_growfs -d /
For an ext4 filesystem, use the resize2fs command instead. For example, if the filesystem is named /dev/nvme0n1p1, you can use this command:
sudo resize2fs /dev/nvme0n1p1
Check that the size of the filesystem has been extended:
df -hT
As you can see, the previous 8gb size is now 16gb.
Congrats! You've just increased the amount of hard disk availability!