From Delta Vmdk: Restore Vm

In the realm of modern virtualization, the ability to manipulate virtual machine (VM) states without disrupting live services is a cornerstone of operational efficiency. At the heart of this capability lies the snapshot mechanism—a technological marvel that allows administrators to preserve the state of a VM at a specific point in time. Central to this mechanism is the "delta VMDK," a specialized file that acts as the differentiating layer between the current state of the VM and its original base disk. Restoring a VM from a delta VMDK is not merely a matter of file retrieval; it is a complex process that requires a deep understanding of virtual disk architecture, dependency chains, and data integrity.

Restoring a VM from a delta VMDK file requires careful planning, attention to detail, and a solid understanding of VMware's virtual disk formats. By following the steps outlined in this story, you can successfully reconstruct a base VMDK file from delta VMDK files and restore your VM to a previous state.

In VMware:

Let's say you have a VMware vSphere environment with several virtual machines. One of your VMs, which we'll call "MyVM," has a virtual disk that is stored as a set of delta VMDK files. Over time, changes have been made to the VM, and the delta VMDK files have grown. You've decided that you want to restore MyVM to a previous state, but you only have the delta VMDK files and not the original base VMDK file.

: The original, read-only virtual disk.

qemu-img rebase -u -b parent-base.vmdk delta.vmdk

Create a dummy parent, then rebase:

No such feature exists today in vSphere or Workstation.