[DRBD-user] DRBD Synchronization Rate Questions

[cptype at yahoo.co.jp]

Hi developers!

Thanks for your great work to develop DRBD.

I'm developing middleware at a Japanese company 
and trying to incorporate DRBD into our project.

As a result of various tests, the following questions were raised.
Could you answer the following questions?

1. Can DRBD only provide up to 80 MB/s of network bandwidth per volume 
during the initial full synchronization?
We did an initial full synchronization in DRBD with the following settings:
(I use a network with a speed of 1.25 GB/s.)
----
resource r0 {
  disk {
    c-plan-ahead      0;
    rsync-rate  8388608;
  }
  net {
    protocol C;
  }
  volume 0 {
    device    /dev/drbd1;
    disk      /dev/vg/lv01;
    meta-disk internal;
  }
  volume 1 {
    device    /dev/drbd2;
    disk      /dev/vg/lv02;
    meta-disk internal;
  }
  volume 2 {
    device    /dev/drbd3;
    disk      /dev/vg/lv03;
    meta-disk internal;
  }
  volume 3 {
    device    /dev/drbd4;
    disk      /dev/vg/lv04;
    meta-disk internal;
  }
  on host01 {
    address   10.1.1.31:7789;
    node-id   0;
  }
  on host02 {
    address   10.1.1.32:7789;
    node-id   1;
  }
  connection {
    host host01 port 7012;
    host host02 port 7021;
  }
}
----
At this time, the overall sync speed was about 320 MB/s.
Then, I increased the number of volumes from the above settings to 8 
and performed an initial full synchronization again, 
and the sync speed was about 640 MB/s.