If you have a need to restore just a single disk of a multi-disk virtual machine and you perform a normal restore, the original VM is deleted as one of the steps in the restore process. You will then be left with a VM with only one disk, which is not the intent and can cause loss of data.
Before performing a restore of a VM, unless you select to restore the VM to another name, the original VM is deleted and replaced by the restored VM.
Please follow these steps to restore a single disk of a multi disk VM on a ESXi host.
1. When restoring the virtual machine, on the Destination Selection page enter another name in the Restore As box when configuring the restore job.
2. For the VM disk(s) that you do not need to restore select Skip this Disk option from the dropdown next to the disk.
3. For the VM disk(s) that you do need to restore select a datastore from the dropdown next to the disk.
4. Complete the restore job and run the restore job.
5. Once the restore job you will now have a new VM in addition to the original VM. On the original VM, remove the disk(s) that need to be to replaced. By right clicking the VM and clicking on "Edit Settings," highlight the disk you wish to remove, click Remove, and then click the "Remove from virtual machine and delete files from disk" radial button.
Note this will have to be done for each disk seperatly if working with more than one disk.
6. On the new restored VM, remove the restored disk(s) so that they can be used by the original VM. By right clicking the VM and clicking on "Edit Settings," highlight the disk you wish to remove, click Remove, and then click the "Remove from virtual machine" radial button.
Note this will have to be done for each disk seperatly if working with more than one disk.
7. Copy or move the disk from the newly restored VM disks to the original VM directory via the datastore browser.
Note you can leave the disks from the restored VM in the new datastore without any issues.
8. On the original VM, select "Edit Settings", "Add," then select "Hard Disk." Click Next. Select "Use an existing virtual disk and click next". Click the Browse button and locate the virtual disk in the restored directory or in the original VM directory depending if you moved the disks in step 7 and click OK. Select the proper Virtual Device Node for the disk. If you are replacing the OS disk, this is probably SCSI (0:1). Click Next and the Finish.
9. Boot the original VM.
10. Delete the restored VM which is no longer needed.
