This month’s tip comes from the Zenoss Users Forum topic Tracking file system growth, not percentage of disk used. The default filesystem graphs show utilization as an overall percentage, but this tip lets you watch the disk usage on filesystems over time. Zenoss Community member Wouter "netdata" D’Haeseleer provides the following:

Instructions

1. Go to the Device Template you want to update (/Devices/Server/SSH/Linux for example)
2. Select the FileSystem Template
3. Add a new Graph Definition and name it Utilization Bytes or whatever you prefer.
4. Add a new Graph Point DataPoint, select the disk_usedBlocks.
5. Select the new usedBlocks and set the RPN value to
   ${here/blockSize},*
6. Save and exit.
7. Go to your device OS tab and select a File System

You should have a nice graph like this:

The nice part of this solution is that Zenoss has been collecting this data so the new graph is automatically filled with historical data. You can go back and add thresholds as you see fit to alert when certain values