raw disk vmdk loses changes upon remount

[loungin]

I am trying to use Ubuntu Linux partitions on my hard drive as a guest OS in VB 3.0.12. I get strange behavior in that I can write to the raw vmdk partition, but upon a remount of that raw partition in the guest system, the disk revert to the original unmodified state. That is, it seems like the partition is effectively read only even though during one mount session it appears as read-write.

My host OS is Vista Premium Home edition. I'm using the PUEL binaries on the web for 32bit Vista.
I created the vmdk files using vmmanage, selecting only the partitions needed by the linux system. Upon booting the machine, it automatically booted grub.

While compiling additions I found that the guest partitions would lose all their changes and revert to the original state upon remounting the partitions, including reboot. For example, I could touch a file in my home directory or edit files and see the changes. Then if I unmount home and remount it, the file is gone.

I used default settings for the vmdk, so I tried normal and write-through but both settings still lose changes to the disk upon remount.

I'm not sure if this is a differencing disk issue. Is it possible to use raw disks as a normal mutable disks in the guest? Or are raw disks always immutable?

Please help me set this up properly and let me know if you need more information. Thanks.

[loungin]

Can anyone confirm or deny this problem? I've upgraded to 3.1 PUEL but the same problem remains. I can see changes when I write to a raw disk partition, but when I remount, all the changes are gone as if the disk were read only. Am I doing something wrong in my setup?

Thanks

[MarkCranness]

What does File>Virtual Media Manager> say about the disk? (Check this while the VM is running.)
Is there a tree with a {hexUUID}.vdi file (or similar) as a child node in a tree under the VMDK file?
VMM can IIRC tell you if a file is immutable, or if not then VBoxManage showhdinfo "<VMDKFile>" should say.

[loungin]

I don't see a tree but showhdinfo gives something like:

UUID: 1857b951-2d23-4a25-8e43-54154b23bb63
Accessible: yes
Description:
Logical size: 305245 MBytes
Current size on disk: 0 MBytes
Type: writethrough
Storage format: VMDK
In use by VMs: Linux (UUID: 465d75ad-fb84-43de-aa9f-b5fe78447762)
Location: c:\...\.VirtualBox\linuxparts.vdi