I'm sure other people can provide more complete answers as far as reporting and such, but our organization has a repository containing over 26TB of images/files and is growing at somewhere around 750GB per month.
Our configuration involves a collection of 4-6TB drives on servers specifically dedicated to hosting the LF Volumes (i.e., separate from the app server) and a single logical volume configured in the LF Admin Console set to roll over at 20GB.
As each physical volume is filled, Laserfiche automatically rolls over to a new 20GB physical volume within that logical volume.
Outside of Laserfiche, we have monitoring tools that check the available space of each drive on the server, and we are alerted when a drive reaches 80%, 90%, and 95% of capacity.
When a drive gets close to capacity, we use the LF Admin console to change the UNC path of the default volume to point to a drive with more available space.
When the current physical volume reaches the 20GB limit, the next rollover volume will be created in the new location meaning we can continue using the same default volume but still have the files distributed across multiple drives and/or servers.
All of our primary documents go through a very specific set of processes and we track a variety of data including image/file sizes in an external database that we use for reporting.
You can find some helpful information about volumes and best practices in this document.