- Veeam Support Knowledge Base
- Appliance Mode (Hotadd) Requirements and Troubleshooting
Appliance Mode (Hotadd) Requirements and Troubleshooting
| KB ID: | 1054 |
| Product: | Veeam Backup & Replication | 6.5 | 7.0 | 8.0 | 9.0 | 9.5 | 10 | 11 | 12 | 12.1 | 12.2 | 12.3 | 12.3.1 | 12.3.2 | 13 | 13.1 |
| Published: | 2011-07-19 |
| Last Modified: | 2026-10-19 |
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Known Issues
- If the VM disk resides on a vVol, the Veeam VMware Backup Proxy's VM configuration file (vmx) must be on the same vVol.
- The Veeam VMware Backup Proxy VM must be located on a host with access to the datastore containing the VM's disks being backed up or replicated, or in the case of a restore operation, where the disks of the restored VM will be placed.
For example, when backing up or restoring to a datastore that is local only to a single host, hotadd will only function if the Veeam VMware Backup Proxy VM is located on that same host so that it can attach the VMDK file to itself. - Ensure that VMware Tools is up-to-date for the Veeam VMware Backup Proxy VM.
- To ensure maximum compatibility, the Veeam VMware Backup Proxy VM's configuration version must be updated.
- A single SCSI controller can have a maximum of 15 disks attached. The exception is a VMware Paravirtual SCSI (PVSCSI) controller on a virtual machine with hardware version 14 or later (ESXi 6.7 and later), which supports up to 64 disks. To run multiple concurrent jobs with more disks than a single controller supports, add more SCSI controllers to your Veeam VMware Backup Proxy server that is responsible for hot-adding the disks.
VMware KB 1037094: Adding a SCSI controller to the virtual machine - HotAdd may fail if any disk was created with a newer hardware version than the VM being backed up. For example, if a disk was moved from a hardware version 8 VM to a hardware version 7 VM. To resolve this, upgrade the hardware version of the VM.
- In the case of a standalone host connection (no vCenter added to the console), only disks of VMs that are located on the same host as the Veeam VMware Backup Proxy can be hot-added. This may require additional proxy servers to be configured on each host in the environment.
- HotAdd may fail if you are trying to back up the VM through the host added as a standalone server into Veeam Backup Infrastructure, which is actually being managed by vCenter. The following error message can be found in the source agent log:
"Reconfigure attempt failed for VM "" with Vmomi::MethodFault::Exception ("vim.fault.HostAccessRestrictedToManagementServer")" - If you plan to process VMs that store disks on an NFS 3.0 datastore, deploying a backup proxy on the same ESX(i) host where these VMs reside is advisable. Veeam KB1681: VM Loses Connection During Snapshot Removal
- Virtual Appliance backup jobs fail after a Veeam VMware Backup Proxy VM has been moved, cloned, or restored. This occurs because the UUID of the proxy VM at the VMware level no longer matches the UUID recorded on the proxy machine.
Veeam KB1332: Hot-Add/Virtual Appliance Failures - HotAdd fails if VM disks being backed up don't have unique disk UUIDs across the vCenter, for example, if such VMs were deployed from a single template to different hosts. VMware previously documented this issue in KB 2006865, and it was observed to occur even in vSphere 7. For assistance with investigating and resolving duplicate disk UUIDs, please get in touch with VMware Support.
- Backup in HotAdd mode may fail if a SATA controller is configured on a proxy virtual machine. VMware previously documented this issue in KB 2151091: HotAdd mode throws error while using SATA controller with proxy virtual machine.
- Hotadd may fail if a replica of the VBR server or any proxies exist under the same vCenter server as the VBR servers or proxies processing the job.
Veeam KB2159: Appliance Mode (Hotadd) isn't available if proxy VM and its replica are running under the same vCenter
Troubleshooting
- Test to see if the disk of the VM to be backed up can be manually hotadded to the proxy. See: http://www.veeam.com/kb1184
- Check all Veeam Proxies for unmounted HotAdded disks and release them manually. See: http://www.veeam.com/kb1775
Please contact Veeam Technical Support for further assistance.
If this KB article did not resolve your issue or you need further assistance with Veeam software, please create a Veeam Support Case.
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