是否有可能在不重写的情况下将数据预置到文件中?

I deal with very large binary files ( several GB to multiple TB per file ). These files exist in a legacy format and upgrading requires writing a header to the FRONT of the file. I can create a new file and rewrite the data but sometimes this can take a long time. I'm wondering if there is any faster way to accomplish this upgrade. The platform is limited to Linux and I'm willing to use low-level functions (ASM, C, C++) / file system tricks to make this happen. The primimary library is Java and JNI is completely acceptable.I deal with very large binary files ( several G