Virtual disk file is equivalent to the physical hard disk of our physical machine. It could contain the operating system that runs on the Virtual Machine itself, as well as the folders and files. When a VM is backed up from the host level, what happens in the background is the VM’s virtual disk file (or files) that makes up the VM itself is copied to another storage. With this way, the administrator could easily restore the entire machine whenever needed. But, there are times when administrator only required to restore a single file that is contained in a virtual hard disk file. With host level backup, the only way to do that is by restoring the entire machine, making it operational, then find the required file within the machine and copy it somewhere. Such a big effort and so much time wasted, as we have to go through the entire machine restoring process just to get a single file within it.
However, there is a way in Windows machine where we can expedite the restoration task and make the process more efficient. Starting on Windows 7, it has provided a feature to mount and browse the content of a virtual disk file. In Windows 8 and Windows 10, this feature is just getting even better. We can do this on either Microsoft Hyper-V virtual disk (VHD or VHDX file) or VMware vSphere virtual disk (VMDK file).
Mount and browse file from VHD file
We can directly mount a Hyper-V virtual disk file from Windows Explorer. Simply right click on the VHD or VHDX file then select Mount. The virtual disk will be treated as an additional drive and can be accessed from This PC. The administrator can easily browse the content like a regular drive, find the files needed, and copy it somewhere else.
Other ways we can mount VHD or VHDX file using Windows machine is by doing it from Disk Management (click Action -> Attach VHD) or using Powershell script that does the same.
Mount and browse file from VMDK file
VMware vSphere virtual machine has its virtual disk in VMDK format. We can’t mount it by directly right click on the VMDK file but we can open Windows Explorer -> right click on This PC -> select Map Virtual Drive -> browse to the folder where we keep the VMDK file and select OK. As the result, the VMDK will be mounted as a separate drive in This PC and administrator can browse into it.
Mount and browse virtual disk file provides easier and faster way to recover a single file within a backup file. However, it is not without its limitation. When the VM is directly attached to an iSCSI or pass-through/raw device mapping (RDM) disks, data stored in this additional storage will not be included in the host level backup because host backup process is unable to see disks that are internally connected to the VM guest OS. So, even if we can mount the VHD or VMDK, we may not find the required files or folders if it is stored on the additional storage. After all, mounting virtual disk does not always works perfectly, and when it happens, another alternative way must be considered.
Avoid having to mount and browse virtual disk file by doing a VM level backup instead of host level backup. The concept of VM level backup is transferring individual files and folder inside the VM guest OS to another storage. This is done automatically by the backup agent software installed on the VM, and it is able to see the content stored in disks that are directly attached to the VM guest OS. The backed up files and folders result will have the same structure as the original ones, and administrator can easily browse through the structure to get the file or files that require being restored. This option provides a more efficient way for the restoration process compared to the host level backup. Iperius provides the capability to do a backup at the VM level, and with its lightweight process that ensures backup will be done as fast as possible without causing any negative impact to the VM performance.