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Service limitations

Service limitations

Limitations might change as capabilities are added, so feel free to check back from time to time.

General restrictions

The following features are not supported, including all properties associated with these features:

  • The following concepts are not supported:

    • IPV6
    • Multiple IP addresses on the same network interface

  • Virtual server instance name change: If you update the name of a virtual server, the name change might not appear consistently in different areas of the IBM Cloud® console. For example, the virtual server name change might not be reflected in the IBM Cloud console, or on the billing invoice, yet it appears correctly in the user's list of running instances.

  • Direct Link on Classic access to VPC is supported through Setting up access to classic infrastructure only. IBM Cloud Direct Link does not have this limitation.

  • Nested virtualization on virtual server instances is not a supported configuration.

Billing note

When the VPC billing system reports network traffic from load balancers and VPNs, the resources are identified with a nonstandard name. The resource is identified by using the prefix instance-, followed by the last 16 digits of the back-end virtual server instance.

For example, if the load balancer UUID is 10000, but it is running in a virtual server instance that has an internal UUID of 75007600770078007900. The last 16 digits of the instance UUID are: 7600770078007900.

The CRN identifies the load balancer as follows:crn:v1:bluemix:public:is:eu-gb:a/0000000001::load-balancer:instance-7600770078007900.

Virtual private cloud restrictions

An IBM Cloud VPC cannot be peered with other VPCs natively. It is possible to connect VPCs by using either Transit Gateway, VPN Gateways, or Floating IPs.

  • Both VPN Gateways and Floating IPs can't use an automatic route advertisement between the two VPCs. Static routes must be used in each VPC to enable layer 3 connectivity between the two VPCs. See Example: Connecting two VPCs by using the VPN for how you can achieve VPC-to-VPC connectivity by using this method.
  • With Transit Gateway, it advertises the root subnets of each VPC allowing traffic to be routed without the use of static routes. For more information, see Getting started with IBM Cloud Transit Gateway.

Compute restrictions

  • Start and Stop actions are not registered under virtual server instance activity in the UI.
  • The placement group of the instance can't be changed after an instance is provisioned with a placement group. You must delete the instance to remove it from the placement group.
  • API support for creating new instances from an existing boot volume is temporarily suspended. For more information, see the API change log.

Storage restrictions

Block Storage volume names must be unique across the entire VPC infrastructure. A volume that is created on VPC compute resources can't have the same name as a volume created on the classic infrastructure. Valid volume names can include a combination of lowercase alpha-numeric characters (a-z, 0-9) and the hyphen (-), up to 63 characters. Volume names must begin with a lowercase letter.

LinuxONE (s390x processor architecture) virtual server instance restrictions

The following feature is not supported:

  • Dedicated hosts
  • VPC Instance Metadata service.

z/OS virtual server instance restrictions