Hello,
I would like to ask if I am making fundamental understanding mistake. I have Dell PowerEdge server, bit old but fortunately still works very fine. it has on-board Gigabit network interface and 2 nos Dual Gigabit network cards (Broadcom 5709 Dual-Port), thus all together 5 Gigabit interfaces connected to 8 port HP Procure Gigabit switch. Then my Synology NAS has Dual port Gigabit interface connected to the same HP Procurve switch. I have configured network bonding for Synology (LCAP) and same has been marked as Trunc on HP Procurve switch.
I have 3, 500 GB iSCSI configured on Synology which are connected to ESXi as VMFS datastores. Then I have created 3 vSwitches as
vSwicth1- ) 1 on board network interface used for management network
vSwitch2 -) 2 interlaces from one card are used for virtual machines network
vSwitch3 -) 2 interlaces from second card are used for vmKernel for iSCSI (with route based IP hash teaming), no redundancy, so I assume, it will act as network bonding.
Then, a Linux CentOS VM which has 3 disks configured on iSCSI VMFS datastore.
Question:
When I start writing on this iSCSI datastore disk, I get currently upto 105 Mbps (max) speed, which is fairly fine for Gigabit interface. My questions is, when my Synology has bonding, my iSCSI has 2 network interfaces configured as route based IP hash teaming, why aren't my both network cards from vSwitch 3 active at the same time providing me 200+ Mbps writing speed?
Shouldn't I expect 2 gigabit ports active at the same time giving me double speed? I see only first network interface from vmKernel active giving max speed of 105 Mbps.
I would appreciate if you please clarify my doubt.
Thanks in advance
Sameer
How many IP connections (unique combinations of source and destination addresses) do you have with that network and storage configuration?
it is always the misunderstanding that lacp will double the speed. LACP will not split packets across multiple interfaces for a single stream. For example a single TCP stream will always send/receive packets on the same NIC.
I just have one single network segment 192.168.72.x/24 (255.255.255.0) => max 254 connections.
Thanks for clarification, however, even if start multiple writing streams of large data, I still see one interface active. Its perfectly fine even if LACP will not split "single" stream, why I do not see other parallel sessions using other interface. It all happens from same source host, I just start writting in background jobs. Do I also need bonding on source? I guess when I use VMFS disk via iSCSI datastore, shouldn't my interfaces on hypervisor handle this?
That wasn't what I meant.
I'm referring to IP address <> IP address connections between ESXi and your storage device.
Have a look at this thread: Increase throughput for iSCSI with multiple nics