How to shrink your full VM-Backups (Windows/Linux)

How to Backup VMware VMs?

If you’ve no salery cap left, like me. You want to use an Open-Source tool.
I’d love to use GhettoVCB: On Github

I’ll list some usecaeses below.

My environment contains:

  • ESX 6.5
  • NFS-Server


Backup single VM:

  • Backup VMs including a list:
  • Backup VMs with an excluding list:
    - vm2 and vm4 will be backed up
    - vm1, vm3 and vm5 will be excluded from the Backup
  • Backup all VMs on ESX:

If your backup is bigger than your used diskspace than you’ve junk left on your harddrive (which was alread deleted).


In this case, you’ve to override it with zeroes, to make your thin-provisioned disk small again.

To do so you just have to type the following command:

Single partition systems:



Download sdelete (windows utility)

Multi partition systems:

If you have multiple disks (var for example), you should use something like this:

If you now backup again, you’ll see that only mostly your used diskspace will remain in your backup.

After overriding the free space with zero’s:

Working as a IT-Operations engineer at NeXenio, a spin-off by Hasso-Plattner-Institute for products around a digitial workspace.

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