I have been researching how to set up a system to automatically upload photos from a DSLR camera to a Wireless Hard Drive. I have seen possible solutions such as using an Eye-Fi SD card, but those require a computer or tablet to run software in order to pull pictures off of the camera. My main question is would it be possible to load an autorun.inf onto the wireless Hard Drive? Is it possible to get the autorun.inf to run without an operating system? Or would i need to to load an operating system onto the wireless hard drive so that the autorun.inf will automatically work? If there is another solution that would work please let me know.
Unless both the camera and the HDD enclosure has this feature to run automated scripts and also support what those scripts contain then...no.
If you have an (maybe old) android phone you might be able to get some OTG-USB hub with card reader and a USB HDD with external power. Then you could use the phones file manager for the transfer. Eye-fi is nice for some snapshots here and there but if we are talking about lots of pictures ... I would not use it for that. Every wireless connection drains battery, so what you save in weight and size of gear, you would have to compensate with more batteries. (I am assuming optimizing your bag is the goal here.)
I actually have a wifi microsd card adapter and not only does it drawn a considerably higher current than a normal card (160mA) it also heats up, which can be a problem too.
Its quite convenient if you are in a air cooled studio environment where you aren't using batteries to power the camera and just need to take a couple pictures at a time. Its not great if you have to use batteries because the current draw is 5x compared to just a microsd card.
Then there is the whole thing about connecting to the storage, which is fine if you have a tablet, laptop or a phone just for that, its next to impossible to connect the card directly to a hdd, and as such you will need a medium that does this for you for ex. the phone or a raspberry pi that runs on batteries, or a tablet or something.
All in all, depends how you use it and if you are fine with lugging extra batteries or a battery grip around.
I'm fine with lugging extra batteries around. What I'm trying to do is make a backpack with a large battery bank integrated into it, and a way to automatically back my photos as I take them.
I do have a raspberry pi that I could set up with the hdd to act as the in between.
You said a wifi SD card generated extra heat and was only good for a few pictures at a time. I usually end up taking about a 1000 pictures a day if Im out with my camera. That may make my plan null and void.
far easier to just make a Rpi that has a SD card adapter that is attached to a hdd, boot it plug in a card and it will empty it to the hdd, boring but works.
Also exists as a product on its own for ex. WD 2TB My Passport Wireless Portable External Hard Drive - WIFI USB 3.0 - WDBDAF0020BBK-NESN
or just get a bunch of 32gb micro sd cards an a carrying case.
if you have a phone you can either use a micro SD with adaptor or a full SD with otg, have 2 of those and then dump them on your phone and/or back them up to Google photos