This is a known issue affecting VMware vCenter Server 6.0.
If there is enough free space available on volume holding the VMware vCenter Server files, this warning may safely be ignored. You can clear the alarm by selecting the Acknowledge and Reset to green options for the triggered alarm.
To work around this issue if the alarm continues to trigger:
- Disable the Inventory Health Alarm in vCenter > Manage > Alarm Definitions.
- Reduce size of volume so there is less than 80% of available free space.