Switch Dell N4032 slow link speed between nodes

Question

Hello,

I have 3 node cluster (Dell Power Edge R640) with EMCv3000 storage connected with fibre optic switches.

The nodes of the server are connected to DellN4032 10gbit switch. The network cards of the nodes are 10 gbits. However, when i am testing the speed between the servers (from disk C to Disk C on every node SSD) the maximum speed size is 200 mb/s. I even cant get near 10 gbit speed. The network speed between these nodes and other servers connected to that switch with 10 Gbit network cards is the same - 200-230 mb/s.

What would be the possible reason for this low speed. Any ideas for troubleshooting ?

Regards,

Daniel Ivanov

DELL-Josh Cr · Answer

Hi, What NIC is in the servers? You are copying between the nodes and not to the EMC v3000 right? How fast does it copy to there?

dragonflybg · Answer

Hi, Josh !

Thank you for your answer !

My network Cards are Broadcom NetXtreme E-Series Advanced Dual-port 10GBASE-T Ethernet.

Yeah, i am copying between the nodes. To be honest, when i am copying inside the array (EMC v3000) i am rarely reaching more than 350 mb/s speed.

DELL-Josh Cr · Answer

Is the NIC firmware and driver up to date? What OS are you using?

dragonflybg · Answer

Everything is up to date. I am using WindowsServer 2016.

DELL-Josh Cr · Answer

So that should be fine, what is the storage inside the servers?

dragonflybg · Answer

Every cluster node includes Raid1 256GB SSD and it is connected to Dell EMC v3000 with capacity of 40 TB.

DELL-Josh Cr · Answer

Try using iperf and seeing if it can transfer faster https://iperf.fr/iperf-download.php

dragonflybg · Answer

I connected 2 additional servers to the switch. The transfer speed between them is 70 mb/s(or 0,5 gbp/s). That is huge performance problem for 10 gbit switch.   Any other ideas ?

DELL-Josh Cr · Answer

Is the switch firmware up to date?

Networking General

Switch Dell N4032 slow link speed between nodes

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