Hi Billy,
I know that I have given information via support issue that you opened with us. I will add the same information here for other community members.
The 0 value for the metric
Custom Metric Host (virtual)|Custom Metric Process (virtual)|Custom Metric Agent (virtual)(collector_host@port)(SuperDomain)|Enterprise manager|Data Store|Volume Space Free: baseline Volume Free (mb)
is a hangover from previous releases. In 10.x the baselines database has been superseded, so this metric is no longer valid. We already have raised a defect with our Engineering team for this. In future releases this will no longer appear in the investigator. For the present we would recommend that you disable or remove from alerts or metric groupings that reference this metric.
Thanks, Amir