There are several methods you can use to migrate a server to the cloud:

• The host or OS cloning technique involves installing an agent on the source system that will clone the OS image of the system. A snapshot is created on the source system and then sent to the target system. This type of cloning is used for a one-time migration. With the OS Copy method, all operating system files are copied from the source machine and hosted on a cloud instance. For the OS Copy method to be effective, the people and/or tool that executes the migration must understand the underlying OS environment.
• The Disaster Recovery (DR) replication technique deploys an agent on the source system that's used to replicate data to the target. However, the data is replicated at the filesystem or block level. A few solutions continuously replicate the data to target volumes, offering a continuous data replication solution. With the Disk Copy method, the disk volume is copied in its entirety. Once the disk volume has been captured, it can be loaded into the cloud as volumes, which can then be attached to a cloud instance.
• For virtual machines, you could use agentless techniques to export/import your virtual machine into the cloud. With the VM Copy method, the on-premise virtual machine image is copied. If the on-premise servers are running as virtual machines, such as VMware or OpenStack, then you can copy the VM image and import it into the cloud as a machine image. One main benefit of this technique is that you can have server backup images that can be launched over and over again.

• With the User Data Copy method, only the application's user data is copied. Once the data has been exported from the original server, you can choose one of three migration strategies—repurchase, replatform, or refactor. The User Data Copy method is only viable for those who know the application's internals. However, because it only extracts user data, the User Data Copy method is an OS-agnostic technique.
• You can containerize your application and then redeploy it in the cloud. With the containerization method, both the application binary and user data are copied. Once the application binary and user data have been copied, it can be run on a container runtime that is hosted on the cloud. Because the underlying platform is different, this is an example of the replatform migration strategy.

Several migration tools in the market can help you migrate your data and/or server to the cloud. Some tools take a DR strategy for migration, and some DR tools also support continuous replication to facilitate live migrations. There are some that specialize in forklifting your servers, performing database migrations across platforms, or database schema conversion. The tool must be able to support business processes that you are comfortable with, and you must have the operational staff to manage it.