Backup of vmdk files

However, virtual machines residing on ESXi servers use a slightly different format of vmdk virtual disks — a virtual disk descriptor and virtual disk extent that contains raw data of the virtual disk are two separate files on the ESXi datastore.

The pattern of a virtual disk descriptor name is diskname. As for virtual disks of the VMware Workstation format, a virtual disk is represented as a single diskname. A virtual disk descriptor defines the structure of the virtual disk, virtual disk geometry, virtual hardware version, and IDs.

A virtual disk descriptor is represented as plain text. On the left side of the screenshot below, you can see a virtual disk descriptor of the ESXi format a vmdk file that can be opened with any text editor. On the right side of the screenshot, you can set eyes on the data of the virtual disk descriptor that is embedded into a single vmdk file of the VMware Workstation format.

The vmdk file is opened in HEX editor. As you can see, the embedded disk descriptor data is written to the monolithic vmdk file of the Workstation format from the 0x address, which is the number of the first byte. If you transform the HEX value to a binary and decimal format, you will get:. This means that if you want to extract the embedded descriptor from the vmdk file, you should extract a portion of data starting from the th byte.

Read the abovementioned blog post to see how to extract, edit and import an embedded virtual disk descriptor. On the screenshot below, have a look at two virtual disk files opened in HEX editor. The same operating system is installed on both virtual disks the first partition used for installing the OS was created and formatted with a built-in Windows disk utility.

On the left side of the screenshot a -flat. The raw data is written from 0x on this virtual disk -flat. On the right side of the screenshot, the virtual disk of the Workstation format is displayed and the same data is written from 0x byte number which is not the beginning of the vmdk file. Before you proceed, it is recommended that you back up your data to prevent any possible virtual disk damage. Perform operations with your disks at your own responsibility and risk. The advantages of these methods are simplicity and universality.

After booting an operating system from a DVD media, you can mount the partitions of your virtual disk and copy files from the virtual disk to a USB hard disk attached to the VM or to your host machine, or to any other machine via the network. Some Live DVD distributions mount disks partitions automatically. This method can be called a legacy method because the principle is similar to copying files from physical disks of physical computers when the installed operating system cannot boot.

Be aware that the operating system booted from Live DVD must recognize file systems of partitions of your virtual disk whose files you want to access.

Using additional tools on Windows may help to resolve this issue. There are two NTFS partitions on the virtual disk — one is the boot system partition and the second is disk C. The official Ubuntu 18 installation ISO image is used in the current example. The file name is ubuntu In our example, copying data to the SMB share will be explained. First, create a directory to be used as the mount point.

Then make sure that the necessary files have been copied, and check the contents of your SMB share. As you can see on the screenshot above, the bootmgr file used in this example has been copied successfully. Now you know the first method of copying the contents of the VMDK file to another location when an operating system installed on a VM cannot boot. This method is similar to the previous one, but a VMDK virtual disk should be attached to an existing virtual machine that has a functioning operating system.

Keep in mind that the functioning operating system on the first healthy VM must be compatible with file systems used on a virtual disk of the second VM that has a non-bootable operating system a VM whose VMDK file you want to attach as an additional virtual disk to extract files. Power off the VM that uses a virtual disk from which files you want to extract.

Find this virtual disk in the ESXi datastore. Copy the virtual disk to another directory on the same datastore or another datastore to prevent an error caused by virtual disk lock. The ESXi host is managed by vCenter.

If you use a standalone ESXi host without vCenter, you can use the logics explained in this example — the differences are only in the user interface. Select destination and hit the Copy button to confirm. In the opened window, select the destination. You can copy the VMDK file to some location on the same datastore or to another datastore. Both vmdk and - flat. Using BackupChain you can schedule live backups of VMware virtual machines to run at any thinkable schedule you want.

It uses deduplication and compression to create small and incremental backups of even very large VMDK files. These increments are also moved faster over the wire if you are backing up to a NAS box, network server, or an FTP server far away. Granular backup is an innovative method BackupChain uses to get access to files inside a VM but accessed from the host.

Instead of backing up your entire VM every hour, you could schedule a second backup task to just back up a folder inside the VM every hour. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Showing results for. Search instead for. Did you mean:. Sign In. Restore VMDK files. Go to solution. Thanks for the help and advice. All forum topics Previous Topic Next Topic. Accepted Solutions. VJware Level 6.

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