One of the most popular and straightforward approaches is the rehost strategy, also known as lift-and-shift. This approach involves migrating applications and workloads to the cloud with minimal modifications, keeping their architecture, configuration, and settings largely unchanged.
Here, we delve into the rehost cloud migration strategy, examining the various tools and services offered by AWS, Azure, and Google Cloud Platform (GCP). We also highlight how these platforms facilitate and streamline the migration process.
What is Rehost Cloud Migration?
The rehost strategy refers to moving applications to the cloud without re-architecting or rewriting them. Applications are “lifted” from their current on-premises environments and “shifted” as-is to a cloud provider, typically using virtual machines (VMs) or containers in the cloud to replicate the original infrastructure.
Benefits of Rehost:
| Speed | Minimal Changes | Cost-Effective | Immediate Cloud Benefits |
| The rehost approach is one of the quickest ways to migrate workloads, as it avoids the complexities of redesigning applications. | No major changes to the application code are required. | It’s often a low-cost initial migration option, allowing enterprises to leverage cloud scalability while lowering migration expenses. | Organizations can start benefiting from the cloud’s elasticity, pay-as-you-go pricing, and scalability without significant upfront investment. |
Rehost Strategy in AWS, Azure, and GCP
All three hyperscalers; Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP) provide comprehensive services and tools to assist with the rehost strategy. We try to go into a detailed overview of the services available today! in each cloud provider for rehosting.
1) Rehosting in AWS
Amazon Web Services (AWS) provides a wide range of tools to simplify the rehosting of on-premises infrastructure to the AWS cloud.
Key Tools and Services for Rehosting in AWS:
| AWS Service | Description |
|---|---|
| AWS Server Migration Service (SMS) | Automates the migration of on-premises workloads to AWS, replicating live server volumes to Amazon EC2. Supports agentless migrations. |
| AWS Application Migration Service (MGN) | Facilitates lift-and-shift by continuously replicating source servers to AWS and converting them to EC2 instances. |
| AWS Snowball | A physical data transfer device for moving large volumes of data to AWS when internet bandwidth is limited. |
| AWS DataSync | Automates data transfer between on-premises storage and AWS storage services like S3, EFS, or FSx for Windows. |
| VM Import/Export | Imports virtual machine images from your on-premises environment (e.g., VMware) to run as EC2 instances in AWS. |
| AWS Elastic Beanstalk | Used for quick deployment of web applications, including those being lifted and shifted, with minimal configuration. |
AWS Rehost Workflow Example:
- Use AWS Server Migration Service (SMS) or Application Migration Service (MGN) to automate the migration of VM workloads.
- Data transfer is handled by AWS DataSync or AWS Snowball (for larger datasets).
- Once the infrastructure is migrated, manage the EC2 instances using tools like AWS Systems Manager.
2) Rehosting in Microsoft Azure
Azure offers a range of services to help businesses migrate on-premises applications and infrastructure to the Azure cloud. Azure’s tools focus on simplifying and automating the migration process, particularly for virtual machines.
Key Tools and Services for Rehosting in Azure:
| Azure Service | Description |
|---|---|
| Azure Migrate | A central hub for planning, assessing, and executing migrations. Supports VMs, databases, and applications. |
| Azure Site Recovery | Originally a disaster recovery tool, now widely used for VM migrations to Azure. Supports VMware and Hyper-V environments. |
| Azure Storage Migration Service | Helps move large data sets from on-premises systems to Azure Blob Storage. |
| Azure VM Import/Export | Enables importing on-premises virtual machine images into Azure to be used as Azure VMs. |
| Azure Data Box | Physical data transfer service for large datasets when network speeds are slow. |
| Azure Virtual Machines (VMs) | Supports the lift-and-shift strategy by providing highly scalable cloud-based virtual machines. |
| Azure Automation | Used for managing and automating post-migration tasks like VM configurations and patching. |
Azure Rehost Workflow Example:
- Use Azure Migrate to assess your existing infrastructure, perform dependency analysis, and estimate costs.
- Use Azure Site Recovery for VM migration or Azure Migrate for larger migrations.
- Transfer data using Azure Data Box for large datasets or Azure Storage Migration Service for smaller volumes.
- After migration, monitor and manage workloads with Azure Automation and Azure Monitor.
3) Rehosting in Google Cloud Platform (GCP)
Google Cloud offers a robust set of migration tools focused on ease of use, automation, and scalability. Google’s rehost solutions are designed to reduce downtime and allow for a seamless migration of workloads from on-premises or other cloud platforms.
Key Tools and Services for Rehosting in GCP:
| GCP Service | Description |
|---|---|
| Migrate for Compute Engine | Facilitates the lift-and-shift of on-premises VMs (VMware, Hyper-V, and AWS) to Google Cloud’s Compute Engine. |
| Google Transfer Appliance | Physical data transfer solution for moving large datasets to GCP when internet speed is insufficient. |
| Cloud Storage Transfer Service | Transfers data from on-premises storage or other cloud providers (AWS S3, Azure Blob Storage) to Google Cloud Storage. |
| VM Migration Service | Automates the migration of VMs to Google Compute Engine, including incremental syncs for reduced downtime. |
| Anthos | Modernizes applications post-migration, enabling them to run across multiple clouds or on-premises with Kubernetes. |
| Google Cloud Deployment Manager | Automates infrastructure management using templates, helping manage workloads after migration. |
GCP Rehost Workflow Example:
- Use Migrate for Compute Engine to lift and shift VMs from on-prem or other cloud platforms.
- For data-heavy migrations, use Google Transfer Appliance or Storage Transfer Service.
- Manage infrastructure post-migration using Google Cloud Deployment Manager or Anthos for hybrid cloud setups.
Lets compare AWS, Azure, and GCP for Rehost Migration
| Feature | AWS | Azure | GCP |
|---|---|---|---|
| Main Migration Tool | AWS Application Migration Service | Azure Migrate | Migrate for Compute Engine |
| Data Transfer | AWS DataSync, Snowball | Azure Data Box, Azure Storage Migration | Cloud Storage Transfer, Transfer Appliance |
| VM Import/Export | AWS VM Import/Export | Azure VM Import/Export | VM Migration Service |
| Post-Migration Management | AWS Elastic Beanstalk, Systems Manager | Azure Automation, Monitor | Google Cloud Deployment Manager, Anthos |
Final Thoughts
The rehost migration strategy offers a quick, straightforward way to move workloads to the cloud with minimal changes. AWS, Azure, and GCP provide powerful tools to support rehosting, along with specialized services for various migration needs.
Using these tools and services, businesses can swiftly transition to the cloud, gaining scalability, cost savings, and agility without the need for extensive re-architecting. Whether migrating virtual machines, data, or applications, these cloud platforms simplify the lift-and-shift process, enabling a smooth and efficient migration.