Comment 0 for bug 1216209

For a cluster, especially one that is managed by DRS, placing a new VM on a datastore accessible to the largest number of the cluster's hosts enables capabilities like vMotion, increases resource management flexibility by DRS; whereas placing it in a datastore that is local only to one host has the opposite effect, as it essentially pins the VM to that one host. Hence the driver should by default favor datastores that are more accessible to the cluster's hosts over those that are not. Having this behavior will likely reduce the number of situations when the datastore_regex has to be configured by the administrator to specified allowed datastores. In the degenerate case where there is only one host in the cluster, a local datastore can still be picked for placement.