Ticket #8485 (new defect)
Differencing disk created from multiattach base disk is marked as auto-reset
|Reported by:||bitcrazed||Owned by:|
|Version:||VirtualBox 4.0.4||Keywords:||differencing disk, multiattach|
According to the VirtualBox docs:
Technically, a "multiattach" image behaves identically to an "immutable" image except the differencing image is not reset every time the machine starts.
This doesn't appear to be the case.
I created a VM with a dynamically sized disk, installed Win7, sysprepped the VM and shut it down. I released the HDD and used VBOXMANAGE MODIFYHD ... -TYPE MULTIATTACH to mark this HDD as immutable and that children should not auto-reset.
I then created a new VM, using the base HD which created a differencing disk for its own data.
Using VBOXMANAGE SHOWHDINFO ..., I examined the new VM's differencing disk and saw that it claims auto-reset is on.
I booted the new machine, completed the OOBE (Out Of Box Experience) and modified the desktop wallpaper. I shut down the VM and then rebooted it and was sent straight back to the OOBE again.
VirtualBox is a great product, but its poor handling of differencing disks, requiring users to delve around in the command-line tools to configure even the most rudumentary differencing scenarios, is, in my opinion, VirtualBox' biggest weakness, especially when compared to Hyper-V and VMWare.
PLEASE fix this bug and consider improving VirtualBox' GUI for handling differencing disks.