Hot-add fails with the error: File is larger than the maximum size supported by datastore

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Hot-add fails
• You see the error:
  
  File is larger than the maximum size supported by datastore `[<datastore_name>] error
  
  
• This issue may occur when using a third party tool to backup a virtual machine.

Environment

VMware ESX 4.1.x
VMware ESXi 4.0.x Embedded
Virtual Disk Development Kit 1.2
VMware Virtual Disk Development 1.2
VMware VirtualCenter 2.5.x
VMware vCenter Server 4.0.x
VMware ESXi 4.1.x Embedded
VMware ESX 4.0.x
VMware ESX Server 3.5.x
VMware ESXi 4.1.x Installable
VMware ESXi 3.5.x Installable
VMware vCenter Server 4.1.x
VMware ESXi 4.0.x Installable
VMware Infrastructure SDK 2.0.x
VMware Consolidated Backup 1.5.x

Resolution

This issue occurs when the backup virtual machine and the VCB-HELPER virtual machine are residing on datastores of different block sizes. This issue occurs when the .vmdk files of the backup virtual machine are greater than the maximum file size supported on the datastore of VCB-HELPER virtual machines.

To work around this issue, ensure VCB-HELPER virtual machines and the backup virtual machine reside on datastores of the same block size.

When choosing a datastore on which to store the files for the backup appliance, choose the datastore with the largest VMFS block size. This is necessary to ensure that the backup appliance can back up virtual machines from all datastores.

Additional Information

For related information, see Add a Hard Disk to the Backup Appliance in the VMware Data Recovery Administration Guide.