You can scale up or scale down the memory, local disk size (/u02), ASM Storage, and CPUs.

Scaling up or down of these resources requires thorough auditing of existing usage and capacity management by the customer DB administrator. Review the existing usage to avoid failures during or after a scale down operation. While scaling up, consider how much of these resources are left for the next VM cluster you are planning to create. Exadata Cloud@Customer Cloud tooling calculates the current usage of memory, local disk, and ASM storage in the VM cluster, adds headroom to it, and arrives at a "minimum" value below which you cannot scale down, and expects that you specify the value below this minimum value.

Cloud tooling provides dbaasapi to identify the minimum required memory. As root user, you have to run dbaasapi and pass a JSON file with sample content as follows. The only parameter that you need to update in the input.json is new_mem_size, which is the new memory to which you want the VM cluster to be re-sized.

cat input.json
{
"object": "db",
"action": "get",
"operation": "precheck_memory_resize",
"params": {
"dbname": "grid",
"new_mem_size" : "30 gb",
"infofile": "/tmp/result.json"
},
"outputfile": "/tmp/info.out",
"FLAGS": ""
}

dbaasapi -i input.json

cat /tmp/result.json
{
"is_new_mem_sz_allowed" : 0,
"min_req_mem" : 167
}

The result indicates that 30 GB is not sufficient and the minimum required memory is 167 GB, and that is the maximum you can reshape down to. On a safer side, you must choose a value greater than 167 GB, as there could be fluctuations of that order between this calculation and the next reshape attempt.

Use the following formula to calculate the minimum required ASM storage:

• For each disk group, for example, DATA, RECO, note the total size and free size by running the asmcmd lsdg command on any Guest VM of the VM cluster.
• Calculate the used size as (Total size - Free size) / 3 for each disk group. The /3 is used because the disk groups are triple mirrored.

• DATA:RECO ratio is:

  80:20 if Local Backups option was NOT selected in the user interface.

  40:60 if Local Backups option was selected in the user interface.

• Ensure that the new total size as given in the user interface passes the following conditions:

  Used size for DATA * 1.15 <= (New Total size * DATA % )

  Used size for RECO * 1.15 <= (New Total size * RECO % )

Scale Down Local Space Operation Guidelines

Scale down operation expects you to input local space value that you want each node to scale down to.

• Resource Limit Based On Recommended Minimums

  Scale down operation must meet 60 GB recommended minimum size requirement for local storage.

• Resource Limit Based On Current Utilization

  The scale down operation must leave 15% buffer on top of highest local space utilization across all nodes in the cluster.

The lowest local space per node allowed is higher of the above two limits.

Run df –kh command on each node to find out the node with the highest local storage.

You can also use the utility like cssh to issue the same command from all hosts in a cluster by typing it just once.

Lowest value of local storage each node can be scaled down to would be = 1.15x (highest value of local space used among all nodes).

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 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. Configure VM Cluster:
      • Click Select DB Servers for VM placement to allocate VM resources.
      • On the Select DB Servers dialog, select a minimum of two database servers for VM placement. 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.
   7. 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.
   8. 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.
   9. 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.
   10. 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.
   11. 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.

   12. 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.
   13. 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 5-8 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%

   14. 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.

   15. 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.
   16. Diagnostic Notification:

       Select the Enable option. Enabling diagnostic notification will allow you and Oracle Support to identify, investigate, track, and resolve guest VM issues quickly and effectively. For more information, see Overview of Database Service Events.

   17. 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. 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.

You can enable or disable diagnostics collection for your Guest VMs after provisioning the VM cluster.

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 the name of the VM cluster you want to enable or disable diagnostic data collection.
5. On the VM Cluster Details page, under General Information, enable or disable Diagnostic Notification.

To add virtual machines to a provisioned cluster, use this procedure.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.

   VM Clusters is selected by default.

2. Choose your Compartment.

   A list of VM Clusters is displayed for the chosen Compartment.

3. Click the name of a VM cluster where you want to add virtual machines.
4. In the VM Cluster Details page, under Resources, click Virtual Machines, and then click Add Virtual Machines.
5. On the Add Virtual Machines dialog, select additional DB servers on which to add the VM.

   You cannot unselect existing DB Servers. The maximum resources available per VM get updated based on the newly added DB servers.

6. To view a list of DB Servers that have more than 2 VM Custers, click Show More.

   Clicking the link opens an overlay panel to list all the VM Clusters running on a particular DB Server.

To view a list of database server hosts on an Oracle Exadata Cloud@Customer system, use this procedure.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Under Infrastructure, click Exadata Infrastructure.
3. In the list of Exadata Infrastructures, click the display name of the infrastructure you wish to view details.
4. Under Resources, click DB Servers.
5. In the list of DB Servers, click the name of the DB Server that you wish to view details.

   DB Server lists VMs from each cluster hosted on them along with resources allocated to them.

To remove a virtual machine from a provisioned cluster, use this procedure.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose the Region and Compartment that contains the VM cluster for which you want to scale the CPU resources.
3. Click VM Clusters.
4. Click the name of the VM cluster for which you want to remove a virtual machine.
5. Under Resources, click Virtual Machines.
6. In the list of virtual machines, click the Actions icon (three dots) for a virtual machine, and then click Terminate.
7. On the Terminate Virtual Machine dialog, enter the name of the virtual machine, and then click Terminate.

   VM removed from the cluster. VM Cluster Details page displays the updated resource allocation details under VM Cluster Resource Allocation.

To modify licensing, be prepared to provide values for the fields required for modifying the licensing information.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose the Region and Compartment that contains the VM cluster for which you want to update the license type.
3. Click VM Clusters.
4. Click the name of the VM cluster for which you want to update the license type.

   The VM Cluster Details page displays information about the selected VM cluster.

5. Click Update License Type.
6. In the dialog box, choose one of the following license types and then click Save Changes.
   • 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.

   Updating the license type does not change the functionality or interrupt the operation of the VM cluster.

1. Open the navigation menu. Under Oracle Database, click Exadata Cloud@Customer.
2. Choose the Region that contains your Exadata infrastructure.
3. Click VM Clusters.
4. Click the name of the VM cluster that you want to add SSH key(s).
5. In the VM Cluster Details page, click Add SSH Keys.
6. In the ADD SSH Keys dialog, choose any one of the methods:
   • Generate SSH key pair: Select this option if you want the Control Plane to generate public/private key pairs for you.

     Click Save Private Key and Save Public Key to download and save SSH Key pair.

   • Upload SSH key files: Select this option to upload the file that contains SSH Key pair.
   • Paste SSH keys: Select this option to paste the SSH key string.

     To provide multiple keys, click Another SSH Key. For pasted keys, ensure that each key is on a single, continuous line. The length of the combined keys cannot exceed 10,000 characters.

7. Click Save Changes.

Starting in Exadata Database Service on Cloud@Customer Gen2, you can scale up or down multiple resources at the same time. You can also scale up or down resources one at a time.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose the Region and Compartment that contains the VM cluster for which you want to scale the CPU resources.
3. Click VM Clusters.
4. Click the name of the VM cluster for which you want to scale the CPU resources.

   The VM Cluster Details page displays information about the selected VM cluster.

5. Click Scale Up/Down.
6. In the dialog box, adjust any or all of the following:
   • OCPU Count:

     The OCPU Count value must be a multiple of the number of virtual machines so that every virtual machine has the same number of CPU cores enabled.

     If you set the OCPU Count to zero, then the VM cluster virtual machines are all shut down. If you change from a zero setting, then the VM cluster virtual machines are all started. Otherwise, modifying the number of enabled CPU cores is an online operation, and virtual machines are not rebooted because of this operation. See also System Configuration.

     Note
     
     If you have explicitly set the CPU_COUNT database initialization parameter, that setting is not affected by modifying the number of CPU cores that are allocated to the VM cluster. Therefore, if you have enabled the Oracle Database instance caging feature, the database instance does not use extra CPU cores until you alter the CPU_COUNT setting. If CPU_COUNT is set to 0 (the default setting), then Oracle Database continuously monitors the number of CPUs reported by the operating system and uses the current count.
   • Memory:

     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.

     When you scale up or down the memory, the associated virtual machines are rebooted in a rolling manner one virtual machine at a time to minimize the impact on the VM cluster.

   • Local file system size:

     Specify the 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 Exadata infrastructure.

     When you scale up or down the local file system size, the associated virtual machines are rebooted in a rolling manner one virtual machine at a time to minimize the impact on the VM cluster.

     Reserved local storage per VM (GB): Displays the size reserved internally for root file systems, Oracle Grid Infrastructure Homes, and diagnostic logs.

   • Usable Exadata storage size:

     Specify the total amount of Exadata storage that is allocated to the VM cluster. This storage is allocated evenly from all of the Exadata Storage Servers. The minimum recommended size is 2 TB.

     You may reduce the Exadata storage allocation for a VM cluster. However, you must ensure that the new amount covers the existing contents, and you should also allow for anticipated data growth.

     Note
     
     When you downsize, the new size must be at least 15% more than the currently used size.

     Modifying the Exadata storage allocated to the VM cluster is an online operation. Virtual machines are not rebooted because of this operation.

7. . Click Save Changes.

Use the console to stop, start, or reboot a virtual machine.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose the Region and Compartment that is associated with the VM cluster that contains the virtual machine that you want to stop, start, or reboot.
3. Click VM Clusters.
4. Click the name of the VM cluster that contains the virtual machine that you want to stop, start, or reboot.

   The VM Cluster Details page displays information about the selected VM cluster.

5. In the Resources list, click Virtual Machines.

   The list of virtual machines is displayed.

6. In the list of nodes, click the Actions icon (three dots) for a node, and then click one of the following actions:
   1. Start: Restarts a stopped node. After the node is restarted, the Stop action is enabled.
   2. Stop: Shuts down the node. After the node is stopped, the Start action is enabled.
   3. Reboot: Shuts down the node, and then restarts it.

Review the health status of a VM cluster virtual machine.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose the Region and Compartment that is associated with the VM cluster that contains the virtual machine that you are interested in.
3. Click VM Clusters.
4. Click the name of the VM cluster that contains the virtual machine that you are interested in.

   The VM Cluster Details page displays information about the selected VM cluster.

5. In the Resources list, click Virtual Machines.

   The list of virtual machines displays. For each virtual machine in the VM cluster, the name, state, and client IP address are displayed.

6. In the node list, find the virtual machine that you are interested in and check its state.

   The color of the icon and the associated text it indicates its status.

   • Available: Green icon. The node is operational.
   • Starting: Yellow icon. The node is starting because of a start or reboot action in the Console or API.
   • Stopping: Yellow icon. The node is stopping because of a stop or reboot action in the Console or API.
   • Stopped: Yellow icon. The node is stopped.
   • Failed: Red icon. An error condition prevents the continued operation of the virtual machine.

To change the compartment that contains your VM cluster on Exadata Database Service on Cloud@Customer, use this procedure.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose the Region and Compartment that contains the VM cluster that you want to move.
3. Click VM Clusters.
4. Click the name of the VM cluster that you want to move.

   The VM Cluster Details page displays information about the selected VM cluster.

5. Click Move Resource.
6. In the resulting dialog, choose the new compartment for the VM cluster, and click Move Resource.

Before you can terminate a VM cluster, you must first terminate the databases that it contains.

1. Open the navigation menu. Under Oracle Database, click Exadata Database Service on Cloud@Customer.
2. Choose the Region and Compartment that contains the VM cluster that you want to terminate.
3. Click VM Clusters.
4. Click the name of the VM cluster that you want to terminate.

   The VM Cluster Details page displays information about the selected VM cluster.

5. Click Terminate.
6. In the resulting dialog, enter the name of the VM cluster, and click Terminate VM Cluster to confirm the action.