Migration preferences for servers

This page describes the available migration preferences for servers in Migration Center.

Google Cloud options

Specify the target product to which you would like to migrate your infrastructure. You can specify either No preference, or one of the following products:

  • Compute Engine
  • Google Cloud VMware Engine
  • Sole-tenant nodes

If you select No preference, Migration Center provides you with recommendations based on the internal default preference logic, which might be updated periodically.

Google Compute Engine

If you select Compute Engine as your target product, specify the different machine series, disk types, and licensing options that you want to apply in your TCO reports.

  • From the Machine types list, select all the Compute Engine machine series that you want to include as possible targets for migration of your virtual machine (VM) instances. To choose the most suitable machine series for your business needs, review the machine families comparison table.

  • From the Disk type list, select your preferred disk type.

  • From the Licensing list, select the type of licensing model you want to apply, for example Pay as you go or Bring your own license.

Google VMware Engine

If you select VMware Engine as your target product, specify the requirements for the group of virtual machines allocated across VMware Engine nodes.


You can configure the level of overcommitment for both CPU and memory. Overcommitment lets you allocate more memory and CPU cores on your VMs than what is available in the physical nodes.

  • The CPU core overcommit ratio lets you specify an overcommit ratio between 1.0 and 8.0, with 0.1 increment. The default value is 4.

  • The Memory overcommit ratio lets you specify the following values: 1.0, 1.25, 1.5, 1.75 and 2.0. The default value is 1.

Deduplication and compression

If you use deduplication and compression in your VMware environment, the Storage savings ratio lets you specify the amount of storage you're expecting to save when you migrate to Google Cloud, based on your current values on-premises. The default value is 1.7.

Sole-tenant nodes

If you select sole-tenant nodes as your target product, specify the node types that you want to see as recommendations in your TCO reports.

Learn more about sole-tenant nodes.

Overcommit factor

If you want to configure overcommit in your target sole-tenant nodes, in the Overcommit factor section, specify a value between 1.0 and 2.0, with 0.01 increment.

Learn more about overcommitting CPUs on sole-tenant nodes.

Host maintenance policy

Specify the host maintenance policy that you want to apply in your target sole-tenant nodes. This might affect the required size of the sole-tenant node cluster that you see in the TCO report.

Learn more about host maintenance policy.

Sizing method

Select the sizing strategy that you want to apply to your VMs in the TCO report. Choose one of the following:

  • No preference: let Migration Center choose the sizing based on the system defaults.
  • No rightsizing: choose a target VM size that closely match the size of your current machines. The algorithm doesn't apply rightsizing, which means that it doesn't consider the current performance data of your machines.
  • Moderate: calculate your target VM size based on the current performance of your machines, and apply moderate rightsizing to your VMs. This approach balances between performance and cost.
  • Aggressive: calculate your target VM size based on the current performance of your machines, and apply aggressive rightsizing to your VMs. For example, if you underutilize your machine CPU, your TCO report will suggest a VM with fewer CPUs. This approach maximizes the use of the VM's resources and reduces costs, but might also impact performance in the event of an unexpected load.
  • Custom: manually configure the parameters that you want the algorithm to use for the calculations. When you choose the custom sizing optimization, you can change the following parameters:
    • Metrics baseline: the baseline for calculating memory, CPU, and disk IOPS.
    • Storage multiplier: the amount of storage that you want to provision in your infrastructure, as a proportion of the current storage utilization.
    • CPU usage: the CPU utilization that you want to have in your infrastructure, as a percentage of the current utilization.
    • Memory usage: the memory utilization that you want to have in your infrastructure, as a percentage of the current utilization.

The following table shows the calculation parameters for the Moderate and Aggressive optimization strategies.

Metric Moderate Aggressive
Metrics baseline 95th percentile 95th percentile
CPU usage 70% 90%
Memory usage 85% 100%
Storage multiplier 1.25x 1.10x
Uptime 730 hours per month 730 hours per month


Specify the outbound traffic that you expect to have. Outbound traffic is the percentage of the total network traffic that leaves the Google Cloud network. You are only charged for outbound traffic.

Pricing track

Specify your preferred pricing track for the VMs that you migrate to Google Cloud.

Choose between a flat-rate, on demand pricing, or a committed use of one or three years. Committed use discounts (CUDs) apply when you choose a committed use, and appear in your TCO report.

What's next