A new SBS 2008 Premium server was setup recently with a 100GB C: system drive and the remainder of the storage space allocated to a D:\ data drive on the main server.
For some reason the C: drive disk space steadily declined down to 50GB and now down to just 2GB free space, whereupon this started to affect system performance and services.
This is verified by right clicking on the C: drive and by selecting properties. However if the C: drive is opened and all of the folders selected, right clicking and selecting properties now shows that only 20GB of the 100GB is taken up. By selecting show hidden files and OS files, this increases to 30GB, but only because the 10GB virtual memory file is now visible.
By moving the system virutal memory file this increased the available C: drive space to just 10GB, which has now mysteriously increased to 14GB two days later.
What could be causing this issue and how can this be resolved?