New issue 45 by hieu.hcmus@gmail.com: [Compact issue] Offset overflow
http://code.google.com/p/weed-fs/issues/detail?id=45
You are using uint32(Maximum 4Gb) to store needle offset(Maximum 32Gb)
when compacting.
Currently It is ok if the volume size is < 4gb
Change variable "offset" in ScanVolumeFile function to uint64 to fix the
issue.