It says that it can. I dedicated 10 GBs for it yet it is not seeing it. I don't want to use a flash drive because they fail, people take them out, they can be broken. That is why I want to raid it with hard drives and have another raid for the NAS files
Yes it
can, but just because it can does not mean that it should.
It won't see the partitions because FreeNAS is designed to take up the entire drive. If you're trying to install FreeNAS to a RAID5 of 3 500GB drives, you're going to be wasting basically 1496GB as FreeNAS will reserve all physical 1500GB for itself as it is designed to take up the entire install drive since it's intended to be installed on a USB drive as a running image.
Also, don't worry about the USB Drive failing, it's a running image, so it's all placed into RAM at boot. For the most part it's only read or written to when changing settings or booting. The back of my NAS where my USB stick is is against an always dark wall, and the USB has a pretty bright status LED. The only times I ever see a flash from back there is at boot or if I change a setting. It's a running image, it lives in RAM, and since a NAS is intended to run 24/7 you'll very rarely ever touch the USB stick. Hell, a physical hard drive would likely die long before a USB stick in this operating mode.
Just make sure you always have a saved version of your configuration.
In the event that you need to change the drive it's as simple as installing the FreeNAS .xz to a new USB, sticking it in the FreeNAS, booting, and uploading the config and you're back like nothing ever happened. Takes ~5 minutes. I have done this before it's not a big deal at all.
If you really don't want to use USB for it, you can get a SATA Flash module, but really all that is is a USB stick that connects via SATA instead, so you're just going to be spending a lot of extra money for the same thing more or less.