XCP-NG all networks are slow < 50MB/s and drops

Hello :slight_smile:

I am using XCP-NG to host my VM’s
I plan to install a physical storage server, in order to avoid the virtual hard drives speed issues.
But for that I need speed when I transfer files from my VMs to this physical server. Unfortunatly I only get 50MB/s (bytes not bits). Sometimes it starts at 90MB/s but always ends to drop at 20MB/s or even 9MB/s !

This is how transfers look like on my network:

VM (NIC-1) → Physical Machine A = 90->50->10MB/s (low and drops)
VM (NIC-1) → Physical Machine B = 90->50->10MB/s (low and drops)

VM (NIC-2) → Physical Machine A = 90->50->10MB/s (low and drops)
VM (NIC-2) → Physical Machine B = 90->50->10MB/s (low and drops)

XCP-NG itself → Physical Machine A = 90->50->10MB/s (low and drops)
XCP-NG itself → Physical Machine B = 90->50->10MB/s (low and drops)

Physical Machine B → Physical Machine B = 110->110->110MB/s (high and stable)

NIC-1 is a 1G card shared with multiple VMs
NIC-2 is a 1G card attached directly to one VM

Physical Machines A&B both have 1G card

Here is a small diagram to help illustrate my words:

VLAN for 192.168.180.0/24 is defined in the VM Test, in the physical switch and in the physical machine A not in XCP-NG or XOA

Here is the NIC I use for the VM Test (NFS Client):

Pool Networks


NFS Client Networks

Do you have any ideas why this is happening ? Do you have the same issue ?
If you need more information please ask.
Thank you very much for you answer :slight_smile:

Some network cards, specifically Broadcom ones can have performance issues. I recommend using Intel based cards. If you already are using Intel based cards then their forums might be able to help Home | XCP-ng and XO forum