DomnesuKernel is 100% compatible with OTG. I checked it by myself. External HDD often required +5V on USB connector even if HDD has external power, check it. What the file system HDD have?The kernel has been installed, everything seems ok (by the app status, like in the above video: OTG mode etc.), but the Galaxy doesn't see the external HDD (provided it with the external power, HDD spinning of course) ... what now? Try another compatible kernel (supposedly there are a few more available)?
Reason is lack of +5V voltage on USB connector of HDD. Fix it. You need take Y usb cable like on the video to power supply and all be working without usb-hub.
Okay. Connect only power connector to USB charger or to working computer, data/power to i9000
For what are you need this old kernel? Many more modern kernels support USB-OTG like MackayKernel, DomnesuKernel or Semaphore...
> adb connect 192.168.1.100 (enter the actual ip address you get for your phone) > adb shell $ su # echo o > /sys/devices/platform/s3c-usbgadget/opmode # cat /proc/kmsg