Please go through the above mentioned blog to understand the checkpoint aka snapshot mechanism in Hyper-v, very less has changes since advent of Hyper-v in 2008 The steps were captured for a .vhd file but the same steps can be followed even if it’s a .vhdx
Before taking these steps, backup all vhd and avhd files to a safe location (Exporting a VM to another volume is a good option).
Caution: Make sure you have enough free space before doing this otherwise the process would fail.
- Make sure the VM is shutdown and we have enough space available usually twice of the snapshot disk.
- Once you have located your snapshot(s) for the VM, rename the most current snapshot to a .vhd and open with the Inspect Disk Wizard from Hyper-V Manager. This will present you with the parent / child relationship of all snapshots.
- Inspect all snapshots until you can recreate the tree back to the main parent vhd. Before moving forward with the merge, you will need to rename all snapshots except the most current snapshot back to avhd in order for the merge to take place.
- Open the Edit Disk Wizard in Hyper-V Manager, browse to the most current snapshot and click next.
- On the next screen, we will choose the option to merge.
- The next screen presents us with a decision to make. If we have multiple snapshots, we will need to choose the option to merge to the parent disk. If you have a single snapshot, you can choose to merge to the parent disk or a new VHD if you want to keep the original parent vhd intact for other data recovery options.
- Click Next, then finish to start the merge. The merge operation may take lot of time (several hours) depending on the size of the snapshots. Keep on merging until you have a final snapshot file. Merge this snapshot to its parent (Main VHD of the VM).
- Once the merge is complete, start the VM to make sure it is intact.