Mentioned before here, but worth mentioning again. If your Apex system gets corrupted and you have to do a restore from a save, it's not as straightforward as you'd hope, and won't work if you just try to run the apexcfg.bin file without preparing the system first. Every attached module has to have the same Aquabus address as in the original setup, and if you don't keep a record of that information before a disaster happens, your chances of having an easy recovery are low.
At the very minimum, save a copy of your system configuration summary page, so that you have a record of which module is at which bus address, as well as other important information that may not be fully restored from the backup file. To do this, pull down the menu under your system name at the upper left of the Apex Fusion dashboard, and select Configuration -> Summary. Then save a full copy of that page. The best way to save it is as a web page, by right clicking and choosing Save Page As... Or you could save the page as a pdf file if you have that ability, or just print it out.