In scenarios where low CPU stability is required or the CPU load is not heavy, you can increase the CPU overcommit ratio of a dedicated host. This way, you can increase the number of available vCPUs on the dedicated host. You can also deploy more ECS instances on the dedicated host and reduce the deployment cost.

Prerequisites

  • The instance type of the dedicated host can be customized. These instance types include g6s, c6s, and r6s. You can configure the CPU overcommit ratio only for custom instance types, such as g6s, c6s, and r6s. For more information, see Dedicated host types.
  • All the ECS instances on the dedicated host are in the Stopped state.

Procedure

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Instances & Images > Dedicated Hosts.
  3. In the top navigation bar, select a region.
  4. Select the dedicated host for which you want to configure the CPU overcommit ratio. On the Dedicated Host tab, choose dropdown-menu>Modify DDH Info.
    modify-ratio
  5. In the Modify DDH Information dialog box, specify the CPU overcommit ratio.
    Valid values of the Custom CPU Oversold Ratio parameter ranges from 1 to 5. The number of available vCPUs of a dedicated host is calculated based on the following formula: Number of available vCPUs of a dedicated host = Number of CPU cores × 2 × CPU overcommit ratio. For example, the number of physical CPU cores on each g6s dedicated host is 52. If you set the CPU overcommit ratio of a g6s dedicated host to 2, the number of available vCPUs on the dedicated host is 208. input-ratio
  6. Click OK.