You can use Deploy CLI to add the disks.
Here is the command syntax to add the disk from the deploy CLI for a HA system.
(ONTAPdeploy) node storage pool attach -cluster-name Sanjeev -node-name Sanjeev-01 -capacity-limit 1TB -name datastore3 -mirror datastore4 -username admin -foreground
Password for admin:
[Request 50164 (success)]: Storage add for node "Sanjeev-01" in cluster "Sanjeev" completed successfully.
(ONTAPdeploy)
Arguments :
Cluster Name: Sanjeev
Node-name: Sanjeev-01
Capacity-Limit: 1TB (Size of the Disk )
Name: datastore 3 ( Name of the Datastore where the vmdk is being created)
Mirror: datastore4 (Name of the Datastore where the mirror vmdk is being created)
Username: admin
Password: ONTAP password.