It was hard to choose topic for my question so I describe my problem.
I have two servers with Proxmox (SERVER1 (proxmox version: 5.4-13) and SERVER2 (proxmox version: 5.2-12)) and two NFS servers (BACKUP and HOME).
HOME is a NAS Synology DS218 connect via LAN.
My problem is totally different transfers between servers and NFS servers.
I've tested using dd transfers. Here are results:
SERVER1 -> HOME:
dd if=/dev/zero of=/mnt/pve/DOM/dwsrv bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 229.058 s, 2.9 MB/s
dd if=/dev/zero of=/mnt/pve/DOM/dwsrv bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 132.96 s, 5.0 MB/s
dd if=/dev/zero of=/mnt/pve/DOM/dwsrv bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 126.139 s, 5.3 MB/s
SERVER1 -> BACKUP (transfers are ok):
dd if=/dev/zero of=/mnt/pve/KIMSUFI-BACKUPER/dwsrv bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 57.4353 s, 11.7 MB/s
dd if=/dev/zero of=/mnt/pve/KIMSUFI-BACKUPER/dwsrv bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 57.3739 s, 11.7 MB/s
dd if=/dev/zero of=/mnt/pve/KIMSUFI-BACKUPER/dwsrv bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 57.7291 s, 11.6 MB/s
SERVER2 -> HOME:
dd if=/dev/zero of=/mnt/pve/DOM/intel bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 35.8503 s, 18.7 MB/s
dd if=/dev/zero of=/mnt/pve/DOM/intel bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 30.0541 s, 22.3 MB/s
dd if=/dev/zero of=/mnt/pve/DOM/intel bs=64k count=10k
671088640 bytes (671 MB, 640 MiB) copied, 44.8764 s, 15.0 MB/s
Speedtest for SERVER1:
Download: 794.86 Mbit/s
Upload: 243.54 Mbit/s
Speedtest for SERVER2:
Download: 827.50 Mbit/s
Upload: 245.85 Mbit/s
Speedtest for HOME (I have 500DL/50UL MBit/s):
Download: 209.42 Mbit/s
Upload: 55.07 Mbit/s
Why I get approx 5 MB/s from SERVER1 to HOME when from SERVER2 to HOME I have approx 18 MB/s?
How can I check, why I get slow transfer from SERVER1 to HOME?
