Quantum 3.5.1 User Manual

Distributed LAN Server/Client Network and Memory Tuning

StorNext User’s Guide

329

Distributed LAN Server/Client Network and Memory Tuning

Using the Distributed LAN Server and Client feature places significant 

additional demands on network capacity and system memory. Before 

creating and using a Distributed LAN Server and Client, review the 

following information:
•

•

1

Due to significant demands placed on the network, the following 

network issues can occur when using Distributed LAN Servers and 

clients:
•

 If the Distributed LAN Server has two 

network interface cards (NICs), each card must have a different 

address and reside on a different subnet. In addition, to take 

advantage of a second NIC in a Distributed LAN Server, the 

Distributed LAN Clients must also have a second connected network 

interface.

•

 Some Ethernet switches may be unable to 

accommodate the increased throughput demands required by the 

Distributed LAN Server and client feature, and will drop packets. 

This causes TCP retransmissions, resulting in a significant 

performance loss. On Linux, this can be observed as an increase in the 

Segments Retransmitted count in 

netstat -s

 output during Distributed 

LAN Client write operations and Distributed LAN Server read 

operations.
To address this issue, edit the 

 configuration 

file and reduce the Distributed LAN Server TCP window size from 

the default value. (Remount the file system after making changes.) 

For additional information about Distributed LAN Client and 

server performance tuning, see the StorNext File System Tuning 

Guide.