Suggested Ethernet Settings for hosts connecting to SymplyPRO Ethernet Appliances

TABLE OF CONTENTS

Windows


In general, it is recommended to apply the following settings in the Windows OS. 

  • Connection speed should be 10Gb. 
    • WARNING: Data Ports will not work at 1Gb
  • Set the MTU size to 9000. 
  • The RX and the TX buffer size should be set to the maximum allowable. 
  • Configure the Windows Registry for iSCSI support 

 

The following iSCSI registry settings are recommended for Windows Hosts connected to the SymplyPRO Ethernet Tape. This will require modifying the Windows registry.


Modify the Registry: 


iSCSI Registry location:

'HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Class/{4D36E97B-E325-11CE-BFC1-08002BE10318}/<instance_number>/Parameters' 


  • set MaxTransferLength to 100000 (hexadecimal). 
  • set MaxBurstLength to 400000 (hexadecimal). 
  • set FirstBurstLength to 100000 (hexadecimal). 
  • set MaxRecvDataSegmentLength to 400000 (hexadecimal). 
  • set InitialR2T to 0 (hexadecimal). 
  • set ImmediateData to 1 (hexadecimal).


Restart the server.


Important: The windows host must be restarted for the registry updates to take effect.


macOS


In general, it is recommended to apply the following settings in the macOS. 

  • Connection speed should be 10Gb.
    • WARNING: Data Ports will not work at 1Gb
  • Set the MTU size to 9000. 

Modify the OS sysctl options:

  • Enable TCP Checksum offloading for Rx and Tx
    • net.link.generic.system.hwcksum_tx=1
    • net.link.generic.system.hwcksum_rx=1
  • Change Rx and Tx Buffer Auto Max to 4 MB
    • net.inet.tcp.autorcvbufmax=4194304
    • net.inet.tcp.autosndbufmax=4194304
  • Responds after every packet (ON)
    • net.inet.tcp.delayed_ack=0
  • Enable HW LRO if it’s not on (gates HW LRO)
    • net.inet.tcp.lro=1
  • Enable TSO if it's not on (gates TSO)
    • net.inet.tcp.tso=1

Modify NSMB configuration:

  • signing_required=no

Here is an example script of how to apply these changes in Terminal:


#!/usr/bin/env bash
# 
# 
# Enable TCP Checksum offloading for Rx and Tx
sudo sysctl net.link.generic.system.hwcksum_tx=1
sudo sysctl net.link.generic.system.hwcksum_rx=1
# Change Rx and Tx Buffer Auto Max to 4 MB
sudo sysctl net.inet.tcp.autorcvbufmax=4194304
sudo sysctl net.inet.tcp.autosndbufmax=4194304
# Responds after every packet (ON)
sudo sysctl net.inet.tcp.delayed_ack=0
# Enable HW LRO if it’s not on (gates HW LRO)
# sudo sysctl net.inet.tcp.lro=1
# Enable TSO if it's not on (gates TSO)
sudo sysctl net.inet.tcp.tso=1
# NSMB configuration
if ! grep "signing_required=no" /etc/nsmb.conf then
    sudo echo "signing_required=no" >>/etc/nsmb.conf
fi

Linux


In general, it is recommended to apply the following settings in the Linux OS


  • Connection speed should be 10Gb.  
    • WARNING: Data Ports will not work at 1Gb 
  • Set the MTU size to 9000
  • In /etc/iscsi/iscsid.conf
    • node.session.iscsi.initialr2t = No
    • node.session.iscsi.immediatedata = Yes
    • node.session.iscsi.firstburstlength = 1048576
    • node.session.iscsi.maxburstlength = 16776192
    • node.conn[0].iscsi.maxrecvdatasegmentlength = 4194304



If you have any questions please submit a [support ticket]