Looking at one of my server nodes under disk volumes, one of the drives was low on space and reporting size, space used, and the percent bar graph. Eventually all the space was consumed and the volume still appears, but the size, space used, and bar graph are blank.
Is this a known bug? I became aware of this issue because I have an alert that warns on low disk space. When disk space available hit 0, the alert condition was being reported as no longer true which I knew was not correct. But the fact that the statistics show as null explains why the condition might not be calculating correctly.