Unable to hot add disk while running backup from VEEAM

Products

• VMware

Issue/Introduction

Unable to hotadd disks to the VM while using VDDK and doing backup via VEEAM

Environment

vCenter Server 8.0

 Windows Server 2012 Standard Edition, 64-bit  (Build 9200)

Cause

In VDDK logs we see below

2024-06-07T05:44:31.243-07:00| host-13584| I125: 2024-06-07T05:44:31.243-07:00 verbose -[13584] [Originator@6876 sub=transport] Released disk [DS NAME] VM NAME/VM NAME.vmdk at SCSI 0:1
2024-06-07T05:44:31.243-07:00| host-14668| I125: 2024-06-07T05:44:31.243-07:00 verbose -[14668] [Originator@6876 sub=transport] SCSI hot-remove was successful for (42357107-1d2c-c74c-4b9f-04cbaf86caa0).
2024-06-07T05:44:31.243-07:00| host-14668| I125: 2024-06-07T05:44:31.243-07:00 error -[14668] [Originator@6876 sub=transport] Mounting 42357107-1d2c-c74c-4b9f-04cbaf86caa0 using transport hotadd failed : .
2024-06-07T05:44:31.243-07:00| host-14668| I125: 2024-06-07T05:44:31.243-07:00 info -[14668] [Originator@6876 sub=transport] Deleted file C:\Users\username\AppData\Local\Temp\vmware-user\42357107-1d2c-c74c-4b9f-04cbaf86caa0-vm-4818570\hotadd\unmount.dat
2024-06-07T05:44:31.243-07:00| host-14668| I125: 2024-06-07T05:44:31.243-07:00 info -[14668] [Originator@6876 sub=transport] Deleted directory C:\Users\username\AppData\Local\Temp\vmware-user\42357107-1d2c-c74c-4b9f-04cbaf86caa0-vm-4818570\hotadd
2024-06-07T05:44:31.243-07:00| host-14668| I125: 2024-06-07T05:44:31.243-07:00 error -[14668] [Originator@6876 sub=transport] Cannot use mode hotadd to access  [DS NAME] VM NAME/VM NAME_1.vmdk: Cannot mount using this method. (Mounting 42357107-1d2c-c74c-4b9f-04cbaf86caa0 using transport hotadd failed : .)
2024-06-07T05:44:31.243-07:00| host-14668| I125: 2024-06-07T05:44:31.243-07:00 verbose -[14668] [Originator@6876 sub=transport] **** TryMode: Use mode nbdssl to access [DS NAME] VM NAME/VM NAME_1.vmdk

While the Veaam backup hot adds the disk to run the snapshot and backup we see in the log that its failing

The cause is the controller type of the disk on the VM

Resolution

We changed the controller type from LSI Logic to Paravirtual to resolve the issue.