Merge vhd files

Specifies that an object is to be passed through to the pipeline representing the merged virtual hard disk. Specifies the path to the child in the virtual hard disk chain that is the source for the merge command. If a filename or relative path is specified, the virtual hard disk path will be calculated relative to the current working directory.

Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Please rate your experience Yes No. Any additional feedback? Module: Hyper-V. Runs the cmdlet as a background job. Report inappropriate content using these instructions. Manually Merge. Any VHD differencing disk avhd will always go to its parent, not the root parent.

So if you have a bunch of AVHDs, Each depends on the one before it - like the rungs of a ladder - they are sequential.

Most folks have a very simple linear chain of snapshots. Click Next through the first screen and select the snapshot file on the following screen. All this being said some people still use snapshots as they can be handy if you are strapped for time and unable to perform a full backup before a major change is applied to a machine. However any snapshot should be deleted in the Hyper-V console and merged ASAP to avoid any problems and prevent extra disk space being used.

After a snapshot is deleted from the console window it is not merged to the parent virtual hard disk until the virtual machine is shutdown. Merging should start automatically when any virtual machine is shutdown. This will merge any deleted snapshots that are associated with that virtual machine to the parent Virtual Hard Disk. Leaving you with no snapshots ready for the machine to be booted up again.

However the bigger the snapshots the longer it takes for them to merge. Another reason why they should not be used in a production environment.

If a snapshot has been ignored for a period of time its associated AVHD will grow in size, using up disk space. This means you could be taking a production server offline for a long period of time while you twiddle your fingers waiting for the merge to finish.

The good news is if it completes the merge successfully happy days! This is because it will merge all the data it needs from the snapshot into the parent virtual disk before it deletes the snapshot, so effectively it copies the data it needs then deletes the snapshot. This is to avoid losing data if the merge fails.

This is a bit of an exaggeration as all of the data from the snapshot might not be copied across to the VHD as it may not all be needed. But this does emphasize the problem. If it is either one of these problems then you will have to merge the snapshots manually. First of all as with anything like this you will want to make sure you backup your data.

Make sure the virtual machine is shutdown and copy the virtual machine hard disks to a safe location as show below:. As you can see there can be a lot to backup.