Google Cloud provides the following options for migrating your servers to Compute Engine.
Importing virtual disks
If you have pre-configured virtual disks in your on-premises environment (sometimes referred to as golden disks or golden images), you can save time by importing those virtual disks into Compute Engine and using the resulting image to create new virtual machines. The import tool supports most virtual disk file formats, including VMDK, VHD, and RAW. For more information, see Importing virtual disks.
To migrate a large number of Virtual Machines, consider one of following VM migration products.
Using Migrate for Compute Engine to migrate VMs
Migrate for Compute Engine provides an agentless cloud migration solution that allows users to efficiently migrate VMs to Google Cloud Platform in minutes. Migrate for Compute Engine uses streaming technology to reduce migration time, provides rightsizing recommendations before you migrate to help you choose appropriate instance types, and integrates with VMware vCenter to provide a single pane of glass for managing VM migrations. Migrate for Compute Engine also offers a web-based interface to organize and automate mass migrations of VMs.
Migrate for Compute Engine is free to use for customers migrating to Google Cloud. Standard billing rates apply for all other Google Cloud products (Compute Engine, Storage, etc.) used or consumed during or after the migration. For example, if you use Compute Engine VMs to deploy Migrate for Compute Engine, you'll need to pay for those instance-hours. Additional information on the Google Cloud products used by Migrate for Compute Engine is available on the Migrate for Compute Engine pricing page.
For more information, see the documentation for using Migrate for Compute Engine to migrate your VMs to Google Cloud.
Using the CloudEndure migration service
CloudEndure provides a simple-to-use managed service for migrations of multiple VMs. It supports on-prem-to-cloud and cloud-to-cloud migrations. CloudEndure's agent-based migration technology supports VMs running in any virtualization environment and also supports physical servers.
The CloudEndure VM migration service is free to use. You will be billed only for the Google Cloud VM resources that you create, based on the Compute Engine price sheet.
For more information, see the Guide for using CloudEndure to migrate your VMs to Google Cloud.
Supported OS versions for migration
In general, virtual machines must be running one of the supported operating systems with the latest version of the kernel for each version of the OS. While some virtual machines with older versions of the kernel may migrate successfully, it is highly recommended that you update to the most recent kernel version. Virtual machines with older kernel versions that do not include drivers for virtio-scsi will fail during migration.