Modifying the SCSI controller on a virtual machine changes the order of the hard disks in VMware vSphere ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:
When you add or modify the SCSI address of a virtual machine hard disk, you experience these symptoms:

• The hard disk display order is different from the original order before the SCSI controller was added or modified
• The hard disks were not removed from the virtual machine

Environment

VMware vSphere ESXi 7.x

Cause

The order of the virtual machine hard disks listed in the VMware vSphere Client and VMware vSphere Web Client is dependent on the hard disk order listed in the virtual machine configuration file. When the SCSI settings of a virtual machine's hard disk is modified, the corresponding entry is removed from the virtual machine configuration file and a new entry is added to the end of the file, resulting in the reordering of the hard disks displayed.

Resolution

This is expected behavior.

 

To retain the preferred hard disk order when adding or modifying the SCSI address of the virtual hard disks:

1. Power down the virtual machine.
2. Log in to the VMware vSphere Web Client.
3. Right-click on the virtual machine from the inventory and select Edit Settings...
4. Remove all hard disks from the virtual machine while retaining the virtual machine disk files.
5. Add each hard disk in the desired order while selecting the preferred SCSI address.
6. Click OK to save the changes to the virtual machine configuration file.

Note: While creating a VM, use EFI instead of legacy BIOS. If the VM is already created with BIOS. If possible recreate a VMX with EFI. 

Additional Information

Example

A virtual machine with 6 virtual disks:

 

Original Configuration:

 

Hard Disk 1- SCSI 0:0

Hard Disk 2- SCSI 0:1

Hard Disk 3- SCSI 0:2

Hard Disk 4- SCSI 0:3

Hard Disk 5- SCSI 0:4

Hard Disk 6- SCSI 0:5

 

We modified these hard disk SCSI addresses:

Hard Disk 2- SCSI 0:1 > SCSI 1:0

Hard Disk 3- SCSI 0:2 > SCSI 2:0

After modifying the hard disks, the hard disks are reordered to:

 

Hard Disk 1- SCSI 0:0

Hard Disk 2- SCSI 0:3

Hard Disk 3- SCSI 0:4

Hard Disk 4- SCSI 0:5

*Hard Disk 5- SCSI 1:0

*Hard Disk 6- SCSI 2:0

 

Note: The modified disks are now displayed as Hard Disk 5 and Hard Disk 6.