Convert virtual disk to RAW disk image

1- Format VBox

vboxmanage clonemedium  ./disk.raw --format=raw

Now disk.raw can be read by mmls to get partition offset.

mmls disk.raw

(ref https://www.andreafortuna.org/2017/06/28/extract-filesystem-bodyfile-from-a-virtualbox-vm/)

2- VMDK

If your mmls support afflib, you can directly process it.

mmls -i afflib vmDisk.vmdk

If yours does not support afflib, you need to convert to raw format using qemu-img

qemu-img convert -f vmdk -O raw vmImage/vm_disk.vmdk vm_disk.raw

Now disk.raw can be read by mmls to get partition offset.

mmls disk.raw

Snapshot:

Lets say the image has 2 snapshot of disk vm_disk.vmdk

File *.vmsd will track this snapshot(mapping snapshot name to the vmdk file). Lets say vmImage.vmsd is as as follow:

.encoding = "UTF-8"
snapshot.lastUID = "2"
snapshot.current = "2"
snapshot0.uid = "1"
snapshot0.filename = "vmImage-Snapshot1.vmsn"
snapshot0.displayName = "asal"
snapshot0.createTimeHigh = "365944"
snapshot0.createTimeLow = "26982807"
snapshot0.numDisks = "1"
snapshot0.disk0.fileName = "vm_disk.vmdk"
snapshot0.disk0.node = "scsi0:0"
snapshot.numSnapshots = "2"
snapshot.mru0.uid = "2"
snapshot1.uid = "2"
snapshot1.filename = "vmImage-Snapshot2.vmsn"
snapshot1.parent = "1"
snapshot1.displayName = "kedua"
snapshot1.createTimeHigh = "365947"
snapshot1.createTimeLow = "170475548"
snapshot1.numDisks = "1"
snapshot1.disk0.fileName = "vm_disk-000001.vmdk"
snapshot1.disk0.node = "scsi0:0"
snapshot.mru1.uid = "1"

This file show the image has 2 snapshot, 'asal' and 'kedua'. 

Snapshot 'asal' point the disk to vm_disk.vmdk. 

Snapshot 'kedua' point the disk to vm_disk-000001.vmdk.

Current state of disk is set in the vmImage.vmx file:

scsi0:0.fileName = "vm_disk-000002.vmdk"

To convert the snapshot disk to raw disk, just pass the any of snapshotXX.diskXX.fileName value(eg: vm_disk-000001.vmdk) to the qemu-img convert as pointed previously.

qemu-img convert -f vmdk -O raw vm_disk-000001.vmdk /tmp/snap_kedua.raw

source: https://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vddk.pg.doc_50%2FvddkDataStruct.5.3.html