Slow copy rate over from the network to the VMs

[cossali98]

I have a Proxmox server with a dozen VMs and a Nas with Truenas. Both of them have Gb/s Thernet ports and are connected to a Gb/s switch
This is the Proxmox configuration:
1 pool called "DATIVM" for VM disks -> raidz 1 of 4 x 600GB SAS 10k rpm disks
1 128 GB SSD -> 60 Gb Os, 2 Gb swap, 50 Gb Cache and 10 Gb log
1 pool called "ISO" containing iso images that I'm going to install on VMs

If I make a copy via network from the NAS to any VM or between one VM and another the copy speed always starts at 100 Mb/s and then goes down to 0 and continuously up and down until the end of the process.If I make a copy over the network to the ISO pool or SSD I don't have this problem.
The Iperf results indicate about 930 Mbits / sec between vm and Nas as also from Proxmox to NAS.

Everything leads me to think that the problem is the disks in the DATIVM pool, but it also seems quite strange to me since we are talking about 10k rpm disks
Anyone have any suggestions on what else to check?

 

[apoc]

Sounds like a typical cache-saturation to me.
These saw-tooth graphs you describe do indicate this.
How do VMs behave if you copy data from SSD to your RaidZ?

 

[cossali98]

Sounds like a typical cache-saturation to me.
These saw-tooth graphs you describe do indicate this.
How do VMs behave if you copy data from SSD to your RaidZ?

Copying from SSD to RaidZ I don't have the problem, I copy around 300 Mb/s

 

[apoc]

In this case this then is likely related to your network (environment, settings, etc.)
Can you explain a in more detail:
What does you setup look like? What is the hardware? The VM-Configuration? the OSes you use? etc.

 

[cossali98]

Proxmox server configuration:
HP DL380 G7
2x Xeon x5670 12 core 2,93 GHz
64 GB of RAM
1 SSD partioned as descripted above
4 x 600GB SAS 10k rpm disks for DATIVM pool
2 x 72 GB 10k rpm disks for ISO pool
4x 1GB/s ethernet port

Switch: Netgear GSM7248R 1 GB/s (every device in my home is connected to this switch and I don't have this issue on the other devices)

VM
I've done the test with a Windows 10 vm (configured as described in the guide https://pve.proxmox.com/wiki/Windows_10_guest_best_practices) and with Ubuntu, both have the problem. The VMs are connected to vmbr0 that's the bridge of the physical ethernet port of server and that's directly connected to the switch. I've tried also changing port but the result doesn't change.