A new vsphere 5 feature which is going to make life a little easier when carrying out data store related work is ‘SDRS maintenance mode’, which allows you to place a data store within a datastore cluster into maintenance mode. Similar to placing an ESX or ESXi host into maintenance mode.
Create a new data store cluster, follow the instructions and select the stores you would like to be part of the data store cluster. In a production environment, it’s recommended that you group datastores with similar storage capabilities.
Once the data store cluster has been created, you can right click a datastore within your cluster and select to ‘Enter SDRS Maintenance Mode’. After work has been completed, exit SDRS Maintenance mode.