[SOLVED] XBMC unable to find /dev/sda

[rasho]

Yes, the drive was NTFS.
I finally found the solution.
Basically it was the problem I suspected from the beggining. RPi did not acquire enough current to start HDD because USB2 only gives 500mA trough the USB. I had to change that from 500mA to 1000mA and it worked instantly. The whole solution is written here: Power 2.5" HDD

Thank you f1vefour for all of your assistance.