To be able to provide Load Balancing and HA for your storage in VMWare vSphere you should use Storage DRS. This feature was introduced for the first time with vSphere 5.0 and needs an Enterprise Plus Licence.
Like DRS for VMs and Hosts, the LUNs will be grouped into a Storage Cluster controlled by the vCenter. If the Performance of a data store decrease or there is no more enough space on one of the data store , vSphere can move VMs to another one. When creating a new VM, you can select on which DRS cluster the VM is to be stored. If data storage is available in the cluster, which are not part of a DRS cluster, these can also be used at this point. The use of Storage DRS does not exclude the parallel use of other data stores.
Creating affinity rules, remove or add a new data store from and to an existing SDRS Cluster is easy and can be configured at any time.
how to activate Storage DRS:
from the Home menu in your vSphere Web client go to Storage
in the Datacenter Menu go to “Datastore Clusters”
and open the Wizard “new Datastore Cluster”
define your own name for the cluster and Turn on Storage DRS
in this screen you should define the automation level of the SDRS you want to use. You can either use the Clsuter settings for all the features or individually activate and deactivate the automation level.
enable I/O for SDRS and choose the appropriate thresholds for your configuration.
here you can control the amount of the used space and the latency of the data stores.
he disk space is specified by a percentage from which storage DRS suggest moving VMs. The latency for accessing the data stores is provided in milliseconds. This determines, for example, whether a data store is heavily or less heavily loaded, and Storage DRS must be activated
select the hosts or Clusters connected to the data store cluster
select the data stores should be added to the SDRS Cluster
The Setup of SDRS is complete.
the context menu of the SDRS cluster allow you to change the settings, add or remove a data store at any time. You can also put one data store in a maintenance mode. SDRS will distribute the residing VMs on this storage to other data stores in the cluster.