data partition is invisible via usb!!! you're talking about the reader partition...
but if the reader partition reverted to 1,4GB, I am afraid that your previous partitioning attempt was not successful, because rooting does not alter partition table....
the meaning of the partitions is documented here in post #37:
https://www.mobileread.com/forums/sho...=163137&page=3
that thread should answer all of your questions
