Cloud Academy Team

Migrating Virtual Machines to the AWS Cloud

Migrating Virtual Machines: why?

In this blog post, we’ll discuss how to migrate your on-premise virtual machines to AWS – focusing mostly on the forklift method – along with key prerequisites and limitations.

Cloud Computing can be described as a metered data center service for running applications at global scale. Instead of having to invest heavily in data centers and physical servers, you can use a cloud computing provider’s servers and only pay for the computing resources you actually consume. Now there’s no need to desperately guess at your future capacity needs: you can access as much or as little as you need, and scale up and down as required. With Cloud Computing, you can easily deploy your application in multiple regions around the world with just a few clicks and provide lower latency and a better experience for your customers at minimal cost. By migrating your application to the cloud you can save on power, cooling, administration, and software licensing costs. Once the move is complete, you’ll be free to concentrate on your application, not on infrastructure

Migrating virtual machines (and the applications they’re running) to the cloud can be cumbersome and complicated unless you use the right tools for the job. Amazon Web Services offers a variety of ways to migrate your applications and servers.

Migration Methods

Forklift: the forklift, or Lift&Shift, a method is best suited for moving a legacy application to the cloud. That is, rather than moving single system components over time, you forklift the whole environment, with all its complex dependencies, in one go.

Hybrid migration strategy: Rather than moving the entire server all at once, individual parts of the application can be moved. This can reduce the risk of unexpected behavior after migration and it is ideal for 3 Tier applications.

Leverage the cloud: Redesign the application with AWS in mind. It might cost a bit more up front, but embedding scalable and manageable services like auto-scaling and edge caching of static content can greatly reduce administration activities – and costs – over the long haul.

Migrating Virtual Machines: the Forklift method:

Let’s look at forklifts in detail:

Fork-Lift VM Migration Workflow
Migrating Virtual Machines: forklift method workflow

1.Identify VM for Lift & Shift

Pre-Requisites

  • Operating systems that can be imported into EC2, Windows: Windows Server 2012 R2 (Standard), Windows Server 2012 (Standard, Datacenter), Windows Server 2008 R2 (Standard, Datacenter, Enterprise),Windows Server 2008 (Standard, Datacenter, Enterprise), Windows Server 2003 R2 (Standard, Datacenter, Enterprise), Windows Server 2003 (Standard, Datacenter, Enterprise) with Service Pack 1 (SP1) or later
  • Linux: Linux/Unix (64-bit)- Red Hat Enterprise Linux (RHEL) 5.1-5.10, 6.1-6.5, CentOS 5.1-5.10, 6.1-6.5, Ubuntu 12.04, 12.10, 13.04, 13.10, Debian 6.0.0-6.0.8, 7.0.0-7.2.0 (RHEL 6.0 is unsupported because it lacks the drivers required to run on Amazon EC2).
  • Image-Formats Supported: RAW format, VHD, VMDK, (you can only import VMDK files into Amazon EC2 that were created through the OVF export process in VMware).

Limitations

  • Imported Red Hat Enterprise Linux (RHEL) instances must use Cloud Access (BYOL) licenses.
  • Imported Linux instances must use 64-bit images. Importing 32-bit Linux images is not supported.
  • Expanded disk image of an imported compressed image cannot exceed 1 TB.
  • Make sure your VM only uses a single disk. Importing a VM using more than one disk is not supported. For Linux VMs, /boot and / can be located in different partitions, but they need to be on the same disk.
  • This method is not recommended for deployments relying on shared storage or very large storage devices.

2.Install the AWS CLI

In order to initiate and manage the migration (import), you’ll need to install the Ec2 CLI tools on the machine where the source images reside. You can refer to AWS documentation for installing CLI tools or view the first video of How to Use the AWS Command-Line Interface course.

3.Migrating virtual machines: prepare your VM

  • Uninstall the VMWare Tools from your VMWare VM.
  • Disconnect any CD-ROM drives (virtual or physical).
  • Set your network to DHCP instead of a static IP address. If you want to assign a static private IP address, be sure to use a non-reserved private IP address in your VPC subnet.
  • Shut down your VM before exporting it.
  • On Windows, enable Remote Desktop (RDP) for remote access, and on Linux enable SSH server access.
  • Allow RDP and SSH access through your host firewall if you have one.
  • Use secure passwords for your all user accounts and disable Auto logon on your Windows VM.
  • Make sure that your Linux VM uses GRUB (GRUB legacy) or GRUB 2 as its boot loader.
  • Make sure that your Linux VM uses one of the following root file systems: EXT2, EXT3, EXT4, Btrfs, JFS, or XFS.
  • Export your VM from its virtual environment for VMware and Microsoft Hyper-V.

4.Execute the VM Export

  • Use ec2-import-instance to create a new import instance task:

ec2-import-instance disk_image_filename -f file_format -t instance_type -a architecture -b s3_bucket_name -o owner -w secret_key -p platform_name

5.Check the VM import status

  • The ec2-describe-conversion-tasks command returns the status of an import task
  • Status values include: active, canceling, canceled, and completed
  • Check the status of your import task:

ec2-describe-conversion-tasks task_id

6.Start your Ec2 Instance

  • Login to your AWS console.
  • In the navigation pane, click Instances.
  • Note the instance ID from VM import status, right-click the instance, select Instance State, and then click Start.

Migrating virtual machines: conclusion

This is one common scenario for migrating virtual machines to AWS.

Before choosing any particular migration approach, make sure you understand both its prerequisites and limitations…then boldly migrate to the cloud!

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