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VMDK Handbook

              by Ulli Hankeln

In emergencies visit Sickbay   


about ...
Is this info trustworthy ?
What is a vmdk-file ?
How to identify the vmdk-type
Sparse and Flat - Thin and Thick

The different types of vmdks

vmdks used as standalone virtual disks
vmdks used to access local physical disks

vmdks used for snapshots or redologs

Platform specifcs ...

Workstation , VMplayer 23 , VMserver 12 , Fusion , ESX and ESXi

The parameters used in a vmdk description

The syntax and valid options
The CID - parameters
How to change the adapter-type of an existing vmdk
How to calculate the disk-geometry


for regular vmdks , physical disks , snapshots , other types

FAQ and Howtos

How to restore a lost vmx-file from a vmware.log
How to restore a lost vmx-file from a vmsn-file
How to restore a lost vmdk-description from a vmware.log
How to safely edit embedded vmdk-descriptions    Read This ! 
How to fix a broken CID-chain
How to create a vmdk-description for a dd-image
How to rewrite monolithicFlat to vmfs format for easy exchange between ESX and Workstation
How to create a vmdk that can be stored on a set of CDs ?
How to check if a snapshot is an orphan ?

Whats better - one-piece vmdks or split vmdks ?
What is the most portable vmdk-format ?

Should I defragment inside my guests ?


test.vmx is not a valid virtual machine configuration file.
Snapshots are not allowed on this virtual machine.
The specified virtual disk needs repair.
Check for missing files failed. The file specified is not a virtual disk.
The parent virtual disk has been modified since the child was created.
The destination file system does not support large files
The version of the virtual disk is newer than the version supported by this program
The SVGA mode stored in the snapshot cannot be restored on this display ...
The suspended image contains a virtual machine that uses floating point features ...


Translating VMware-Snapshotmanager button-names to common sense ...
How to fix a broken CID-chain
Can I recover data from an orphaned snapshot ?
Can I use ESX-snapshots in Workstation ?
Snapshots and linked clones ...
How to create a monolithicSparse - snapshot from scratch
How to check if a snapshot is an orphan


How can I scan for vmdk-files ?
How to fake a basedisk ...


Create regular SPARSE vmdks : vmware-vdiskmanager    vmkfstools
Create regular FLAT vmdks : vmware-vdiskmanager    vmkfstools
Create vmdk descriptions for physical disks : vboxmanage   the hard way
Create a snapshot for an existing vmdk : vmrun    vdk     the hard way
Mount a partition of a vmdk : vdk   vdk64    vmware-mount    imdisk    winimage
Mount a partition of a vmdk on a remote host : vmware-mount
Extract data from a vmdk : dsfo    dd
Inject data into a vmdk : dsfi     dd
Manipulate the disk-layout of a FLAT vmdk : iscsi
Expand an existing vmdk : vmware-vdiskmanager     vmkfstools    fsz - the hard way
Tools to expand an existing snapshot : the hard way
Format Conversions : vmware-vdiskmanager , vmkfstools , Starwind V2V Converter

Commercial data-recovery tools that can handle vmdks

This list is very short - I only recommend tools that I have successfully used myself.
UFS-explorer - you can download a trial before you buy it
Ontrack Easy Recovery - some older versions are freeware now

Commercial data-recovery companies that can handle VMFS-filesystem

Several companies will tell you that they can recover lost data from VMFS - volumes
but as far as I know only Ontrack is certified by VMware.
Their service is rather expensive - it often maybe cheaper to reproduce the data.


© Ulli Hankeln 2010