I created a fixed VHD size 800GB. However, when I try to install CentOS 6 x64 bits OS, it only use 127GB LVM volume. How to install CentOS 6 without using LVM? I want to use all the 800GB disk. Thanks.
You might be presenting your VHD to your VM as an IDE emulated device. I'd suggest you try showing it as SCSI devices or update your Hyper-V setup. I know a bug was filled at least 1.5 years ago about that - I don't know if there's a fix available though. I don't use Hyper-V much.
Without getting too much into details: your virtual IDE disks present itself as an 'ATA-0' device (version 0). This device would supposedly not support LBA48 addressing. System then fallback to 28-bits addressing, showing a limit around 137GB.
Sorry, this isn't really 'clean' answer, but at least you know the issue.