Missing 700Gb+ on Raid 10 - Windows 8

[ja1nsa]

No idea what is happening - help ...

I purchased a new 3Tb external drive a few weeks ago and moved a few directories (mostly media) from my Raid 10 partition. All looked good with a nice chunk of space on all drives available. Yesterday I checked and my Raid 10 was down to 110Mb from 1.83Tb total? I have emptied recycle bin, but still only 130Mb free. A boot shows non of the 4 x 2Tb raid 10 disks are faulty. Any suggestions? I used to run Intel RST, but since I upgraded to W8 a year or so ago I do not seem to have this software installed? it used to rebuild the raid from time to time and I wonder if this is what I should try? Any ideas how to install Intel RST? does it work on W8?

Thanks in advance for any advise.
J.

 

[Pinhedd]

Windows 8 includes native RST drivers, but the ones distributed from Intel come with a nice control panel and some system services.

I'm not quite sure what your problem is, but what I'm concerned about is why a RAID10 logical drive has only 1.83TiB of addressable space. If it is 4 x 2TB in RAID10, it should contain ~3.72TiB, not 1.83TiB.

A single 2TB hard disk will contain 2 * (10^12/2^40) = ~1.83 TiB of addressable space.

A single 3TB hard disk will contain 3 * (10^12/2^40) = ~2.73 TiB of addressable space.

The MBR partitioning scheme is used by the legacy BIOS firmware interface to boostrap the PC. It uses 32 bit logical block addressing with 512 byte blocks, limiting the total addressable space on any logically addressed device to 2^32 * 512 bytes = 2.2TB.

The newer GPT partitioning scheme is used by the more recent UEFI firmware interface to bootstrap the PC. It uses 64 bit logical block addressing with 512 byte blocks, limiting the total addressable space on any logically addressed device to 2^64 * 512 bytes = some huge number.

UEFI firmware can interpret both MBR and GPT partitioning schemes but BIOS firmware can interpret only the MBR partitioning scheme. Furthermore, Windows supports GPT only on 64 bit versions and will use MBR for 32 bit versions.

The combined volume of two striped 2TB hard disks, or one single 3TB hard disk exceeds the maximum logically addressable space possible on BIOS firmware. This is known as the 2.2TB barrier. It can be addressed at the driver level, but the partitioning scheme must still be GPT to use more than 2.2TB of space. PCs with BIOS firmware are unable to boot from logical drives exceeding 2.2TB in size without first limiting the capacity of that drive to 2.2TB.

To see if this is the case, follow these instructions:

Go to Disk Management

find the drive that you're looking for

right click

go to properties

Select the Volumes tab

Take a look at "Partition Style"

My suspicion is that it will say "Master Boot Record (MBR)"

If you are running a 64 bit OS with compatible UEFI firmware you may see the option to convert the disk to a GPT partitioning scheme. If this is available, do so.

 

[ja1nsa]

Hi Pinhedd

Wow - great response. I will check later today as I am working at the moment. Will advise outcome, but quick glance and to assist. I am running i7 870 on 1156 P5p77 Asus Board, so no UEFI. Also, I have adobe cloud (they are largest programs on my rig).