The datastore charts contain information about disk usage for datastores. The help topic for each chart contains information about the data counters displayed in that chart. The counters available are determined by the collection level set for vCenter Server.
Space in GB Space Utilization By File Type Space Utilization by Virtual Machine Storage I/O Control Normalized Latency Storage I/O Control Aggregate IOPs Storage I/O Control Activity Average Device Latency per Host Maximum Queue Depth per Host Read IOPs per Host Write IOPs per Host Average Read Latency per Virtual Machine Disk Average Write Latency per Virtual Machine Disk Read IOPs per Virtual Machine Disk Write IOPs per Virtual Machine Disk Virtual Machine Observed Latency per Datastore