On ESX 9.0 no option to create 4kn VMDK on local 4Kn SCSI HDD datastore

Products

• VMware vSphere ESXi

Issue/Introduction

• On an ESX 9.0 host, a VMFS6 datastore is created on a local 4Kn SCSI  HDD datasatore.
• However, there is only an option to create a VMDK with 512 sector size. There is no option to create a VMDK with 4kn sector size.

Environment

• VMware vSphere ESX 9.0

Cause

• Local VMFS datastore supports homogeneous VMDK types, 512n VMDK on 512 back-end device and 4Kn VMDK on 4Kn backed device.
• The only exception is the 4Kn SCSI local HDD that ESX always presents as 512e. And supports 512n VMDKs only.

 

• Supported format type can be confirmed by running :

 esxcli storage core device capacity list

Device                Physical Blocksize  Logical Blocksize      Logical Block Count          Size               Format Type
--------------------  ------------------  -----------------      -------------------       -----------           -----------
naa.############             4096                512                 3516328368            1716957 MiB            4Kn SWE

 

4K SWE indicates that ESX is emulating 512 bite sector size. (512e)

Resolution

• Observed behavior is expected and by design. 
  
  
• Local 4Kn SSD and NVMe devices are supported for 4Kn VMDK sector size 

Additional Information

See: Sector Formats for Storage Devices