Replication speed is slow with NDB mode with 10Gb network

[zhang_johnson]

Hi everybody,

Currently we are using Veeam 8 B&R to backup and replicate. we have a physical Veeam backup server and using SAN mode to to backup, which has very good speed ( 200MB/s+). However, with the same source and same SAN mode at the source side, the replication speed to another vSphere cluster is pretty slow ( less than 120MB/s). because we only have one Veeam backup & proxy server, so NBD mode is used at the target side.

We have tested that if we deploy an extra proxy server at the target side, which will allow the replication job use HOTADD mode at the target side. The replication speed has been improved to 200MB/s+.

Our env:

source side : vSphere 5.5 U2, 8Gbps SAN, 10Gbps LAN, virtual vCenter Server.
target side : vSphere 5.5 U2, 8Gbps SAN, 10Gbps LAN, virtual vCenter Server.

The source and target side ESXi hosts are in the same subnet and end-to-end 10Gbps LAN .

Is this speed normal for NBD mode replication or we can tune it to be faster?

Thanks!

[foggy]

ESXi management interface, which is used to populate data on target when NBD is used, is throttled by VMware, so speeds you're seeing are expected.