VMDK size displayed in decimal value

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• VMDK size is displayed in decimal value.
• Issue is seen mostly with disk size > 1TB.
• Backup for these VMs may fail.

Environment

VMware vSphere ESXi 7.0
VMware vSphere ESXi 7.x

Cause

• The problem here is that UI accepts configuration in terabytes and also decimal values while backend only accepts integer values in bytes.

Resolution

• The vSphere UI accepts configuration in terabytes and decimal values. However, the backend only accepts integer values in bytes.
• For example, if we take a VM with disk size of 1.6TB which means 1.6TB = 1759218604441.6B this byte value is rounded to 1759218604442 so that backend accepts it.
  Then when the Edit settings in the vSphere UI is invoked again the value 1759218604442B = 1.600000000000364
• On other hand 1.5TB = 1649267441664B and there is no such problem with that value
• Instead of 1.6TB we could use the value of 1.625TB or 1.75TB which represent even numbers in bytes. Or they could try inputting the value in gigabytes.

 

Additional Information

• Unable to change VMDK size to integer value
• Backup of these VMs will fail.