After a few weeks of researching which type of NAS (Network Attached Storage) system I wanted, I ultimately went with FreeNAS (0.686.4 revision 3374).
One thing that bothered me was that on the Status/System page, it only showed the percent used and maximum space, along with a graphic bar representing the same info. If you mouse-over the light-colored area of the bar, it’ll show you how much space is free, as you can see below.

I would like to see how much used and free space there is for each drive at a glance, without having to mouse-over anything. Yes, I’m lazy, but not so lazy that I couldn’t find the code to change the system status display to my liking. Here’s the results…

In order to do this, you have to navigate to the Advanced/Edit File menu at the bottom of the navigation panel on the left side of the page. Once you’re there, type “/usr/local/www/index.php” (without quotes) into the File path box, and then click the Load button. From here, you will have to modify a line of code.
Find:
echo sprintf(gettext("%s of %sB"), $diskusev['capacity'], $diskusev['size']);
and change to:
echo sprintf(gettext("%s of %sB (%sB Used / %sB Free)"), $diskusev['capacity'], $diskusev['size'], $diskusev['used'], $diskusev['avail']);
Once you’ve changed that line, click the Save button. The change will be effective immediately, so navigate to the Status/System page to see the results.
You will notice that the Free space + Used space doesn’t equal the total size that is shown. For my system, I reserved 8% “Minimum free space” when formatting the drives. So I believe the erroneous total figure is a bug, because it doesn’t take into account the “Minimum free space” that you reserved. Perhaps I’ll look into fixing that at a later time, but for now, enjoy the hack.
Keep in mind that if you upgrade your version of FreeNAS, you will probably have to do this again.
-Trystian

