The VM cluster provides a link between your Exadata Database Service on Cloud@Customer infrastructure and Oracle Databases you deploy.

The VM cluster contains an installation of Oracle Clusterware, which supports databases in the cluster. In the VM cluster definition, you also specify the number of enabled CPU cores, which determines the amount of CPU resources that are available to your databases

Before you can create any databases on your Exadata Cloud@Customer infrastructure, you must create a VM cluster network, and you must associate it with a VM cluster.

To connect to the VM cluster virtual machine, you use an SSH public key.

ssh-rsa AAAAB3NzaC1yc2EAAAABJQAA....lo/gKMLVM2xzc1xJr/Hc26biw3TXWGEakrK1OQ== rsa-key-20160304

To create your VM cluster, be prepared to provide values for the fields required for configuring the infrastructure.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose the Region that contains your Exadata infrastructure.
3. Click VM Clusters.
4. Click Create VM Cluster.
5. Provide the requested information on the Create VM Cluster page:
   1. Choose a compartment: From the list of available compartments, choose the compartment that you want to contain the VM cluster.
   2. Provide the display name: The display name is a user-friendly name that you can use to identify the VM cluster. The name doesn't need to be unique because an Oracle Cloud Identifier (OCID) uniquely identifies the VM cluster.
   3. Select Exadata Database Service on Cloud@Customer Infrastructure: From the list, choose the Exadata infrastructure to host the VM cluster. You are not able to create a VM cluster without available and active Exadata infrastructure.
   4. Select a VM Cluster Network: From the list, choose a VM cluster network definition to use for the VM cluster. You must have an available and validated VM cluster network before you can create a VM cluster.
   5. Choose the Oracle Grid Infrastructure version: From the list, choose the Oracle Grid Infrastructure release (19c and 23ai) that you want to install on the VM cluster.

      The Oracle Grid Infrastructure release determines the Oracle Database releases that can be supported on the VM cluster. You cannot run an Oracle Database release that is later than the Oracle Grid Infrastructure software release.

   6. Choose an Exadata image version:
      • Exadata infrastructure with Oracle Linux 7 and Exadata image version 22.1.10.0.0.230422:
        • The Change image button is not enabled.
        • The Oracle Grid Infrastructure version defaults to 19.0.0.0.0.
        • The Exadata guest version will be the same as that of the host OS.
      • Exadata infrastructure with Oracle Linux 8 and Exadata image version 23.1.3.0.0.230613:
        • The Exadata guest version defaults to the latest (23.1.3.0).
        • The Oracle Grid Infrastructure version defaults to 19.0.0.0.0
        • The Change image button is enabled.
        • Click Change image.

          The resulting Change image panel displays the list of available major versions of Exadata image (23.1.3.0 and 22.1.3.0).

          The most recent release for each major version is indicated by "(latest)".

        • Slide Display all available versions.

          Six past versions including the latest versions of Exadata images 23.1.3.0 and 22.1.3.0 are displayed.

        • Choose a version.
        • Click Save Changes.
   7. Configure VM Cluster:
      • Click Select DB Servers for VM placement to allocate VM resources.
      • On the Select DB Servers dialog, select a minimum of one database server for VM placement. If you require a high availability database service that remains available during maintenance and unplanned outages, select at least two database servers. Maximum resources available for allocation per VM are based on the number of database servers selected.
        Note
        
        

        • DB Servers, which already have 8 VMs running on them are not available for selection.
        • When calculating maximum local storage resources across selected DB Servers, the reserved local storage needed by the system to host a VM based on hardware generation is deducted from the DB Server with the least resources.

          For example, if the local storage available across selected DB servers is 823 GB for DB Server 3 and 813 GB for DB Server 4, then the minimum across selected servers is 813 GB and the maximum available for resource allocation is 813 GB - 184 GB (reserved local storage for hosting VM on X8M DB servers) = 629 GB.

          For more information, see Estimating How Much Local Storage You Can Provision to Your VMs.

      • Click Save Changes.
   8. Specify the OCPU count per VM: Specify the OCPU count for each individual VM. The minimum value is 2 OCPUs per VM (for a live VM condition), unless you are specifying zero OCPUs (for a shutdown VM condition).

      If you specify a value of zero, then the VM cluster virtual machines are all shut down at the end of the cluster creation process. In this case, you can later start the virtual machines by scaling the OCPU resources. See Using the Console to Scale the Resources on a VM Cluster.

      The value for OCPU count for the whole VM Cluster will be calculated automatically based upon the per VM OCPU count you have specified and the number of physical Database Servers configured for the system. There is one VM created on each physical Database Server available.

      OCPU: An Oracle Compute Unit (OCPU) provides CPU capacity equivalent of one physical core of an Intel Xeon processor with hyperthreading enabled. Each OCPU corresponds to two hardware execution threads, known as vCPUs.

      See, Oracle Platform as a Service and Infrastructure as a Service – Public Cloud Service DescriptionsMetered & Non-Metered.
   9. Requested OCPU count for the VM Cluster: Displays the total number of CPU cores allocated to the VM cluster based on the value you specified in the Specify the OCPU count per VM field. This field is not editable.
   10. Specify the memory per VM (GB): Specify the memory for each individual VM. The value must be a multiple of 1 GB and is limited by the available memory on the Exadata infrastructure.
   11. Requested memory for the VM Cluster (GB): Displays the total amount of memory allocated to the VM cluster based on the value you specified in the Specify the memory per VM (GB) field. This field is not editable.
   12. Specify the local file system size per VM (GB): Specify the local file system size for each individual VM. The value must be a multiple of 1 GB and is limited by the available size of the file system on the X8-2 and X7-2 infrastructures.

       Note that the minimum size of local system storage must be 60 GB. In addition to the 60 GB, each node of the VM must have at least 137 GB free for miscellaneous VM files. Each time when you create a new VM cluster, the space remaining out of the total available space is utilized for the new VM cluster.

       For more information and instructions to specify the size for each individual VM, see Introduction to Scale Up or Scale Down Operations.

   13. Reserved local storage per VM (GB): Displays the local storage size reserved internally for root file systems, Oracle Grid Infrastructure Homes, and diagnostic logs. This field is not editable.
   14. Configure the Exadata Storage: The following settings define how the Exadata storage is configured for use with the VM cluster. These settings cannot be changed after creating the VM cluster.
       • Specify Usable Exadata Storage: Specify the size for each individual VM. The minimum recommended size is 2 TB.
       • Allocate Storage for Exadata Snapshots: Check this option to create a sparse disk group, which is required to support Exadata snapshot functionality. Exadata snapshots enable space-efficient clones of Oracle databases that can be created and destroyed very quickly and easily.
       • Allocate Storage for Local Backups: Check this option to configure the Exadata storage to enable local database backups. If you select this option, more space is allocated to the RECO disk group to accommodate the backups. If you do not select this option, you cannot use local Exadata storage as a backup destination for any databases in the VM cluster.

       Table 4-12 Storage Allocation

       Storage Allocation	DATA Disk Group	RECO Disk Group	SPARSE Disk Group
       Exadata Snapshots: No Enable Backups on Local Exadata Storage: No	80%	20%	0% (The SPARSE disk group is not created.)
       Exadata Snapshots: No Enable Backups on Local Exadata Storage: Yes	40%	60%	0% (The SPARSE disk group is not created.)
       Allocate Storage for Exadata Snapshots: Yes Enable Backups on Local Exadata Storage: No	60%	20%	20%
       Allocate Storage for Exadata Snapshots: Yes Enable Backups on Local Exadata Storage: Yes	35%	50%	15%

   15. Add SSH Key: Specify the public key portion of an SSH key pair that you want to use to access the VM cluster virtual machines. You can upload a file containing the key, or paste the SSH key string.

       To provide multiple keys, upload multiple key files or paste each key into a separate field. For pasted keys, ensure that each key is on a single, continuous line. The length of the combined keys cannot exceed 10,000 characters.

   16. Choose a license type:
       • Bring Your Own License (BYOL): Select this option if your organization already owns Oracle Database software licenses that you want to use on the VM cluster.
       • License Included: Select this option to subscribe to Oracle Database software licenses as part of Exadata Database Service on Cloud@Customer.
   17. Diagnostics Collection:

       By enabling diagnostics collection and notifications, Oracle Cloud Operations and you will be able to identify, investigate, track, and resolve guest VM issues quickly and effectively. Subscribe to Events to get notified about resource state changes. For more information, see Getting Started with Events.

       Note
       
       You are opting in with the understanding that the list of events, metrics, and log files collected can change in the future. You can opt out of this feature at any time.

       • Enable Diagnostic Events: Allow Oracle to collect and publish critical, warning, error, and information events to me.
       • Enable Health Monitoring: Allow Oracle to collect health metrics/events such as Oracle Database up/down, disk space usage, and so on, and share them with Oracle Cloud operations. You will also receive notification of some events.

       • Enable Incident Logs and Trace Collection: Allow Oracle to collect incident logs and traces to enable fault diagnosis and issue resolution.

         All three checkboxes are selected by default. You can leave the default settings as is or clear the checkboxes as needed. You can view the Diagnostic Collection settings on the VM Cluster Details page under General Information >> Diagnostics Collection.

         • Enabled: When you choose to collect diagnostics, health metrics, incident logs, and trace files (all three options).

         • Disabled: When you choose not to collect diagnostics, health metrics, incident logs, and trace files (all three options).

         • Partially Enabled: When you choose to collect diagnostics, health metrics, incident logs, and trace files ( one or two options).
   18. Show Advanced Options:
       • Time zone: The default time zone for the Exadata Infrastructure is UTC, but you can specify a different time zone. The time zone options are those supported in both the Java.util.TimeZone class and the Oracle Linux operating system.
         Note
         
         

         If you want to set a time zone other than UTC or the browser-detected time zone, then select the Select another time zone option, select a Region or country, and then select the corresponding Time zone.

         If you do not see the region or country you want, then select Miscellaneous, and then select an appropriate Time zone.

       • Tags: Optionally, you can apply tags. If you have permission to create a resource, you also have permission to apply free-form tags to that resource. To apply a defined tag, you must have permission to use the tag namespace. For more information about tagging, see Resource Tags. If you are not sure if you should apply tags, skip this option (you can apply tags later) or ask your administrator.
6. Optionally, you can save the resource configuration as a stack.
   • To save the resource configuration as a Stack:
     1. Click Save as Stack.
     2. In the resulting Save as Stack dialog, provide the following details:
        1. Name: (Optional) Provide an easy to remember descriptive name.
        2. Description: (Optional) Enter a short description.
        3. Compartment: Select a compartment where this Stack will reside.
        4. Tags: Add tags.
     3. Click Save.

        After saving the Stack, the system displays a banner with a link to the saved Stack.

     4. Click the link to open the Stack in the Resource Manager Service console.

        See, Resource Manager and Terraform.

   • To view the details of a Stack:
     1. Open the navigation menu. Under Developer Services, click Resource Manager.
     2. Click Stacks.
     3. Click the name of the Stack that you want to view details.

        Or, click the Actions menu (three dots), and select the View stack details option.

7. Click Create VM Cluster.

   The VM Cluster Details page is now displayed. While the creation process is running, the state of the VM cluster is Pending. When the VM cluster creation process completes, the state of the VM cluster changes to Available.