PlateSpin Protect 10.2
When protecting a workload to a VC/ESXi 5.0 container, the Recovery Point snapshots are stored with the target disks (VMDKs)
Due to a change in behaviour in ESXi 5.0 the Configuration Datastore setting (called the Recovery Point Datastore in Protect 10.1 and earlier) only defines where the target VM's .VMX file is to be kept, whereas in ESX/ESXi 4.1 or earlier this setting also defines where the Recovery Point snapshots are to be held. For ESXi 5.0 (whether managed through a VC 5.0 server or not) the Recovery Point snapshots will be kept in the same datastore as the target disk/s.
The following VMWare KB article has more information as to why this change in behaviour happens:
Due to the fact that the snapshots are being held in the same datastore as the target disks, there may be an incorrect space-related validation against the Configuration Datastore. To avoid any space-related validation issues it is best if the Configuration Datastore is set to the same datastore as at least one of the target disks.