Ticket #6307 (new defect)

Opened 8 years ago

Last modified 8 years ago

Partitions larger than 2T are not supported with Raw disks

Reported by: NeuralMonk Owned by:
Priority: major Component: virtual disk
Version: VirtualBox 3.1.4 Keywords: 2T, raw disks, large disks, GPT, partition tables
Cc: Guest type: other
Host type: other


Trying to create a raw partition for an 8TB Array on the host machine. The partition IS created but will not mount on the guest. The code for the creation of the raw disk looks correct, but the problem is the partition table in my opinion.

On the host, file -t sees this raw disk as a ext3 file system. On the guest, the same command sees the raw disk as data.

My proof to this is that listpartitions command only sees 2TB.

VBoxManage internalcommands listpartitions -rawdisk /dev/sdc

Sun VirtualBox Command Line Management Interface Version 3.1.4
(C) 2005-2010 Sun Microsystems, Inc.
All rights reserved.

Number  Type   StartCHS       EndCHS      Size (MiB)  Start (Sect)
1       0xee  0   /0  /1   1023/254/63       2097151            1

parted -l shows:

Model: TRUSTED Mass Storage (scsi)
Disk /dev/sdc: 8796GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system  Name  Flags
 1      17.4kB  8796GB  8796GB  ext3

My guess, having just scanned the code is that the problem lies within /src/VBox/Frontends/VBoxManage/VBoxInternalManage.cpp

In the partRead, starting at line 646, it looks we are using u32 instead of u64.

That may be just part of the problem as 8T needs a GPT partition table and I am not sure that VB will read that correctly. I would need to do more research to find that out myself and learn the VB code.

Because the bug exists on the host in reading the partition table in the first place, I am unsure of the VBox.log file needed. I have attached a file with the host trying to connect using a

The drive itself is a Drobo connecting via USB.

The reason this is a MAJOR priority is that this disk is a USB drive and ticket 4261 would also solve my problem. But seeing as that is listed as minor and 8 months old, and VB will only give ~600kB/s bandwidth to USB devices, this becomes a MAJOR priority to guests working with large files. Either solution would work.

As it stands right now, VBox is NOT able to deal with large files or large systems.


VBox.log Download (68.8 KB) - added by NeuralMonk 8 years ago.
VBox.log of guest machine trying to access large disk array via rawdisk

Change History

Changed 8 years ago by NeuralMonk

VBox.log of guest machine trying to access large disk array via rawdisk

comment:1 Changed 8 years ago by klaus

Your proof is rather incomplete, but in the end it has some correctness nevertheless. VirtualBox doesn't support GPT at all, and parted does. A traditional partition table can only represent up to 2T of data.

Contributions appreciated, will speed up progress in this area.

Note: See TracTickets for help on using tickets.
ContactPrivacy policyTerms of Use