I wanna back up my Gamecube game library onto my external hard drive. For my Wii games I have already done this using USB Loader GX and I want to know if there are any Loaders like that available for Gamecube games.If more details are required I can update the question immediately.
As far as I know, there aren't any USB loaders for Gamecube games right now. It may be a while, if they ever get developed. The Gamecube didn't have USB in its original hardware and Gamecube mode on the Wii locks down all Wii specific hardware. Theoretically, if someone were to write a custom MIOS (handles Gamecube mode) that could access Wii hardware, it might be possible to make a Gamecube USB loader. However, it would take a lot of time and energy to reverse engineer the current MIOS and modify it to allow access to Wii hardware. I do believe there is potential in Gamecube USB loaders, but it may be a very long time before anyone succeeds in creating one.