Hello

Are you sure that you have access to all 8TB of space from within the operating system? Your configuration should not work. In order for the OS to address more than 2TB it needs to be in GUID partition tables(GPT), but MBR boot mode does not allow addressing of the boot drive beyond 2TB. The R900 does not have UEFI boot mode to support GPT boot beyond 2TB.

Thanks

Probably three VD's and not actual partitions.

hi thanks for the reply

you are correct it should say three VD's rather than partitions

 hello

the raid has three VD's not partitions, the first therefore the boot is 350Gb is formatted NTFS and is the system drive, the remaining are added as GPT drives within 2K8R2, as I said the problem is that bitlocker cant encrypt the third drive.

thanks for your reply 

That makes more sense. There is no hardware configuration I'm aware of that would stop bitlocker from working. This is likely a software issue. I suggest reviewing your configuration to make sure you meet the requirements. One setting that can differ between disks/partitions is whether or not it is dynamic. Bitlocker does not support dynamic volumes. I suggest reviewing Microsoft articles on the requirements.

https://technet.microsoft.com/en-us/library/hh831507(v=ws.11).aspx

https://technet.microsoft.com/en-us/library/cc732774(v=ws.11).aspx#BKMK_R2disks

Thanks