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Best Practices for Veeam Backup & Replication 7.0 for VMware

Veeam Management Pack Help Center  > Best Practices for Deployment & Configuration >  Resource Planning and Optimization > Planning for Proxies > Choosing Transport Mode

Choosing Transport Mode

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For physical proxies, Direct SAN mode is recommended; remember that this mode requires the physical server to be provisioned with access to the storage subsystem, either via Fiber Channel or iSCSI.

Direct SAN iSCSI could be done within a VM if you connect the VM to the iSCSI network and assign the VMFS volume to the in-guest iSCSI software controller.


Before assigning the VMFS volumes to a proxy server, install the backup software or proxy role to that server first.

For virtual proxies, you can use Virtual Appliance (HotAdd) mode. Remember that this mode requires that the proxy server be located on a VM in the same cluster/host as the VM you are backing up. If you are using local production storage, install the backup proxy on a VM on every ESX(i) host.

Using multiple proxies will allow for multi-processing of VMs/VM disks (different VM disks will be processed by different proxy servers).


Due to known limitations, a HotAdd proxy can process one VM disk from the same VM at a time, so it is recommended to configure several smaller proxies instead of a single big proxy if using this mode.

Network mode can be useful in cases where architectures allow for 10Gb connectivity to the ESX(i) hosts management interfaces (otherwise it is used only as a fallback mode when other modes are not available).

Using this mode requires that you install a proxy on any server on the storage network. If you plan to use parallel processing of multiple VM disks, check that max concurrent tasks number is adjusted accordingly on your proxies (see for details). Consider that for NBD there is a limit of 7 concurrent tasks per ESX(i) host.


If a datastore cannot be accessed by Direct SAN or Virtual Appliance (HotAdd) mode by any proxy, then the system will use Network mode to retrieve the VM disks via the ESX(i) management interface.


Due to known limitations for VMs residing on NFS storage (, it is recommended to force using Network mode to backup these machines.

When using Network mode, Veeam Backup & Replication attempts to locate a proxy that is on the same subnet as the ESX(i) management interface to reduce the risk of crossing slow, layer-3 networks. In this mode, the VM data is transferred over the IP management network, so it is important that this network has the ability to handle sustained high-speed data transfer without interfering with normal management traffic.


If you plan to deploy proxy server(s) on existing VM(s), and then such virtual proxy is set up to backup or replicate itself, be aware that CBT will get disabled on it, and the job will automatically failover to Network mode.

This might impact performance (especially noticeable for bigger VMs), so it is recommended that you use another proxy server to back such VM(s) up.

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