I met this problem when writing large files to Intel P4600, which should be able to write at full speed under 10G network. The weird thing here is that I was able to write large files at full 10G network speed when install OMV in ESXI as a virtual machine(P4600 passedthrough), but after I install OMV as baremetal, the write speed drops to about 700mb/s every 10 seconds. I am wondering if this is a driver issue. I tested speed with a windows desktop, mounting P4600 as a SMB share folder. MTU on both ends are set to default value(1500). The file system is ext4.
Any comment would appreciated. Thank you in advance.