There are three different types of EBS volumes available today, each with their own sets of performance characteristics and associated costs. Let's briefly look into each one of them and their potential uses:

Now that we have a fair idea of what an EBS Volume is, let's look at some simple ways that you can create, attach, and manage these volumes.

To view and access your account's EBS Volumes using AWS Management Console, simply select the Volumes option from the EC2 dashboard's navigation pane, as shown here:

This will bring up the Volume Management dashboard as shown here. In my case, I already have a volume present here that is shown as in use. This is our first instance's root device volume that we launched in Chapter 3, Images and Instances. Each EBS-backed instance's volume will appear here in the Volume Management dashboard. You can use this same dashboard to perform a host of activities on your volumes, such as create, attach, detach, and monitor performance, to name a few.

You can view any particular EBS Volume's details by simply selecting it and viewing its related information in the Description tab, as shown. Here, you can view the volume's ID, Size, Created date, the volume's current State as well as its Attachment information, which displays the volume's mount point on a particular instance. Additionally, you can also view the volume's health and status by selecting the Monitoring and Status Checks tab, respectively. For now, let's go ahead and create a new volume using the volume management dashboard.

Creating EBS volumes

From the Volume Management dashboard, select the Create Volume option. This will pop up the Create Volume dialog box as shown here:

Fill in the details as required in the Create Volume dialog box. For this tutorial, I went ahead and created a simple 10-GB general purpose volume:

• Type: From the Type drop-down list, select either General Purpose (SSD), Provisioned IOPS (SSD), or Magnetic as per your requirements.
• Size (GiB): Provide the size of your volume in GB. Here, I provided 10 GB.
• IOPS: This field will only be editable if you have selected Provisioned IOPS (SSD) as the volume's type. Enter the max IOPS value as per your requirements.
• Availability Zone: Select the appropriate availability zone in which you wish to create the volume. Remember, an EBS volume can span availability zones, but not regions.
• Snapshot ID: This is an optional field. You can choose to populate your EBS volume based on a third party's snapshot ID. In this case, we have left this field blank.
• Encryption: As mentioned earlier, you can choose whether or not you wish to encrypt your EBS Volume. Select Encrypt this volume checkbox if you wish to do so.
• Master Key: On selecting the Encryption option, AWS will automatically create a default key pair for the AWS's KMS. You can make a note of the KMS Key ID as well as the KMS Key ARN as these values will be required during the volume's decryption process as well.

Once your configuration settings are filled in, select Create to complete the volume's creation process. The new volume will take a few minutes to be available for use. Once the volume is created, you can now go ahead and attach this volume to your running instance.

Attaching EBS volumes

Once the EBS volume is created, make sure it is in the available state before you go ahead and attach it to an instance. You can attach multiple volumes to a single instance at a time, with each volume having a unique device name. Some of these device names are reserved, for example, /dev/sda1 is reserved for the root device volume. You can find the complete list of potential and recommended device names at http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/device_naming.html.

The following screenshot shows the option of attaching a volume:

To attach a volume, select the volume from the Volume Management dashboard. Then select the Actions tab and click on the Attach Volume option. This will pop up the Attach Volume dialog box, as shown:

Type in your instance's ID in the Instance field and provide a suitable name in the Device field as shown. In this case, I provided the recommended device name of /dev/sdf to this volume. Click on Attach once done. The volume attachment process takes a few minutes to complete. Once done, you are now ready to make the volume accessible from your instance.

Accessing volumes from an instance

Once the volume is attached to an instance, you can basically format it and use it like any other block device. In this case, I'll be using the same Amazon Linux instance that we created back in Chapter 3, Images and Instances. You can attach and mount volumes to Windows-based instances as well.

To get started, first up connect to your running instance using putty or any other SSH client of your choice. Next, type in the following command to check the current disk partitioning of your instance:

# sudo df -h

You should see a /dev/xvda1 like filesystem mounted on the root (/) partition along with few other temp filesystems, as shown here. This is more or less the standard disk partitioning scheme that your instances will have.

Next, run the following command to list out partitions on your current instance. You should see a default /dev/xvda partition along with its partition table and an unformatted disk partition with the name /dev/xvdf as shown in the following screenshot. The /dev/xvdf command is the newly added EBS volume that we will need to format in the upcoming steps:

# sudo fdisk -l

Once you have verified the name of your newly added disk, you can go ahead and format with a filesystem of your choice. In this case, I have gone ahead and used the ext4 filesystem for my new volume:

# sudo mkfs -t ext4 /dev/xvdf

Now that your volume is formatted, you can create a new directory on your Linux instance and mount the volume to it using your standard Linux commands:

# sudo mkdir /my-new-dir
# sudo mount /dev/xvdf /my-new-dir

Here is the screenshot of creating new directory using the preceding commands:

Here's a useful tip! Once you have mounted your new volume, you can optionally edit the Linux instance's fstab file and add the volume's mount information there. This will make sure that the volume is mounted and available even if the instance is rebooted. Make sure you take a backup copy of the fstab file before you edit it, just as a precautionary measure.

Detaching EBS volumes

Detaching EBS volumes is a fairly simple and straightforward process. You will first need to unmount the volume from your instance and then simply detach it using Volume Management dashboard.

Run the following command to unmount the EBS volume from the instance:

# sudo umount /dev/sdf

Note

Make sure you are unmounting the correct volume from the instance. Do not try and unmount the /dev/sda or any other root partitions.

Once the volume is successfully unmounted from the instance, detach the volume by selecting the Detach Volume option from the Actions tab, as shown here:

You can create, attach, and manage EBS volumes using the AWS CLI as well. Let's go ahead and create a new EBS volume using the AWS CLI. Type in the following command:

# aws ec2 create-volume 
--size 5 --region us-west-2 --availability-zone us-west-2a 
--volume-type gp2

The following code will create a 5 GB General Purpose volume in the us-west-2a availability zone.

The new volume will take a couple of minutes to be created. You should see a similar output as the following screenshot. Make a note of the new volume's Volume ID before proceeding to the next steps.

Now that the new volume is created, we can go ahead and attach it to our instance. Type in the following command:

# aws ec2 attach-volume 
--volume-id vol-40993355 
--instance-id i-53fc559a 
--device /dev/sdg 

The following command will attach the volume with the volume ID vol-40993355 to our instance (i-53fc559a), and the device name will be /dev/sdg. Once again, you can supply any meaningful device name here, but make sure that it abides by AWS's naming conventions and best practices as mentioned in http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/device_naming.html.

Once the volume is attached to your instance, the next steps are pretty easy and straightforward. First format the new volume with a suitable filesystem of your choice. Next up, create a new directory inside your instance and mount the newly formatted volume on it. Voila! Your volume is now ready for use.

You can detach and delete the volume as well using the AWS CLI. First up, we will need to unmount the volume from the instance. To do so, type in the following command in your instance:

# unmount /dev/sdg

Make sure you are unmounting the correct volume and not the root partition. Once the volume is unmounted, simply detach it from the instance using the following AWS CLI code:

# aws ec2 detach-volume 
--volume-id vol-40993355

The output of the preceding command is as follows:

Finally, go ahead and delete the volume using the following AWS CLI code:

# aws ec2 delete-volume 
--volume-id vol-40993355

Remember that you cannot delete volumes if they are attached or in use by an instance, so make sure that you follow the detachment process before deleting it.

We do know for a fact that AWS automatically replicates EBS volumes so that your data is preserved even in case the complete drive fails. But this replication is limited only to the availability zone in which the drive or EBS volume was created, which means if that particular availability zone was to go down for some reason, then there is no way for you to back up your data. Fortunately for us, AWS provides a very simple yet highly efficient method of backing EBS volumes, called as EBS snapshots.

An EBS snapshot in simple terms is a state of your volume at a particular point in time. You can take a snapshot of a volume anytime you want. Each snapshot that you take is stored incrementally in Amazon S3, but, you will not be able to see these snapshots in your S3 buckets; they are kind of hidden away and stored separately.

You can achieve a wide variety of tasks using snapshots. A few are listed as follows:

To create a snapshot of your volumes, all you need to do is select the particular volume from the Volume Management dashboard. Click on the Actions tab and select the Create Snapshot option, as shown here:

You should see the Create Snapshot dialog box as shown in the following screenshot. Provide a suitable Name and Description for your new snapshot. An important thing to note here is that this particular snapshot is not supporting encryption, but why? Well, that's simple! Because the original volume was not encrypted, neither will the snapshot be encrypted. Snapshots of encrypted volumes are automatically encrypted. Even new volumes created from an encrypted snapshot are encrypted automatically. Once you have finished providing the details, click on Create to complete the snapshot process:

You will be shown a confirmation box, which will display this particular snapshot's ID. Make a note of this ID for future reference.

The new snapshot will take a good 3–4 minutes to go from Pending to Completed. You can check the status of your snapshot by viewing the Status as well as the Progress fields in the Description tab, as shown here:

Once the snapshot process is completed, you can use this particular snapshot and Create Volume, Copy this snapshot from one region to another, and Modify Snapshot Permissions to private or public as you see fit. These options are all present in the Actions tab of your Snapshot Management dashboard:

But for now, let's go ahead and use this snapshot to create our very first AMI. Yes, you can use snapshots to create AMIs as well. From the Actions tab, select the Create Image option. You should see the Create Image from EBS Snapshot wizard as shown here. Fill in the required details and click on Create to create your very first AMI:

The details contain the following options:

Click on Create to complete the AMI creation process. The new AMI will take a few minutes to spin up. In the meantime, you can make a note of the new AMI ID from the Create Image from EBS Snapshot confirmation box, as shown:

You can view your newly created AMI under the AMIs option from the EC2 dashboard's navigation pane:

So, here we have it! You very own AMI, created and ready to use.

An important point to note here is that you will not be able to delete this particular EBS Snapshot now as it is in use by your AMI. You will have to deregister your AMI first from the AMI Management dashboard and then try and delete the snapshot.