The initial vCPU, memory, and disk resources available to a database VM are determined by the VM class you selected and the disk size value that you specified when you created the database VM. You can later adjust the resource configuration at runtime.
Considerations
VMware Data Services Manager supports increasing vCPU and memory, but not decreasing. The same applies to changing the number of replicas. You can increase the number of replicas/nodes, but not decrease.
Sufficient resources must be available to scale the compute configuration or to extend the virtual disk. VMware Data Services Manager returns an error resources are insufficient.
Only the owner of the database VM and the DSM Admin have the privileges required to change the resources allotted to the database VM.
Scaling the Compute Configuration
When you change vCPU and memory amounts, you choose from a predefined set of VM classes that provide vCPU/memory amount combinations.
Scaling vCPU or memory resources is an on-demand operation. When you initiate the operation, VMware Data Services Manager powers down the database VM, applies the new resource settings, and then powers the database VM back up. In addition to the service being offline during this period, the downtime affects currently running management tasks as follows:
- If an automated task is running when the scaling request is made, the task may fail, but will be automatically re-initiated in the next maintenance window.
- If scaling coincides with other running on-demand tasks, those tasks may also fail, and you may be required to re-initiate them.
Extending the Virtual Disk Size
You may choose to extend the virtual disk size of a database VM when your data storage requirements for the service change. VMware Data Services Manager supports only extending the disk size; you can not reduce the size of the virtual disk.
Extending disk is an on-demand operation. VMware Data Services Manager immediately initiates the task, and performs the operation without any downtime to the database VM or the service.
By default, VMware Data Services Manager backs up the service before extending the virtual disk. While it is not recommended, you can omit this step if you choose.
Update Database VM Resource Configuration
Perform the following procedure to scale up the vCPU or memory resources allotted to a database VM.
When you change the compute configuration of a database VM, VMware Data Services Manager powers down the database VM, applies the new resource settings, and then powers the database VM back up. This action will interrupt service activities, and may also cause running management tasks to fail.
Prerequisites
- Before scaling the compute resources of a database VM, ensure that any currently running management and service tasks first complete, or are nonessential.
- Before extending the virtual disk of a database VM, ensure that the database VM has no snapshots. For more information, see Determining if a virtual machine running on a snapshot and Managing snapshots in vSphere Web Client knowledge base articles.