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NetApp NFS Plug-in for VMware VAAI: Lazy Zeroed disks are incorrectly reported as Eager Zeroed

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Applies to

  • VMware vSphere
  • NetApp NFS Plug-in for VMware VAAI
  • NFSv3

Issue

In a vSphere environment the following issue is encountered:

  • A newly provisioned Lazy Zeroed Thick (LZT) disk will be reported in vCenter as Eager Zeroed Thick (EZT)
  • The NetApp NFS Plug-in for VMware VAAI is installed in ESXi 

Because disks are incorrectly labeled as EZT instead of LZT the following may happen:

  • Any clones of a virtual machine (VM) that contain disks that were provisioned as LZT, but are incorrectly labeled as EZT, will result in a cloned VM with inflated (zeros written) EZT disks
  • During storage vMotion, due to the incorrect EZT label, provisioned LZT disks will be inflated (zeros written) on destination

To illustrate this issue:

1. New LZT disk is created. Note the 'du -h' output reflects that there is no data written to the vmdk:

[root@esx1:/vmfs/volumes/6bd191da-62ff2ac3] vmkfstools -c 10G -d zeroedthick LZT.vmdk
Create: 100% done.

[root@esx1:/vmfs/volumes/6bd191da-62ff2ac3] du -h LZT-flat.vmdk
0       LZT-flat.vmdk

 

2. Within vCenter the disk is reported as EZT:

clipboard_e713643b0f6c0d4117e57dbfec15f1fa0.png

 

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