Chapter 3 System Preparation
160 September 2002 HPSS Installation Guide
Release 4.5, Revision 2
gatherperformance data using a variety of settings to determine the optimal combinations.
The primary values that govern performance include send/receive buffers, size of reads/
writes, andrfc1323 value for high performance networks (HIPPI, G-Enet). Create a table
showing these values. An example table can be found below:
To test the receiving machines performance issue:
% ttcp -r -s -b<bsize> -l<lsize>
To test the sending machines performance issue:
% ttcp -t -s -b<bsize> -l<lsize> <hostname/interfacename>
Thefollowing is an example of the information to be gathered from the above commands
(assumesen0 is 10 MB Ethernet, if en0 is Fast or G-Enet,rfc1323 should be on:
Receiver Table
Interface Bsize Lsize RFC1323 Performance CPU utilization
en0 16k 16k Off -- --
en0 16k 8k Off -- --
en0 64k 64k Off -- --
en0 64k 32k Off -- --
...
ccs0 64k 64k On -- --
ccs0 64k 32k On -- --
...
Sender Table
Interface Bsize Lsize RFC1323 Performance CPU utilization
en0 16k 16k Off -- --
en0 16k 8k Off -- --
en0 64k 64k Off -- --
en0 64k 32k Off -- --
...
ccs0 64k 64k On -- --
ccs0 64k 32k On -- --
...
What you are looking for are the best values possible for each network connection. These
values will be used in turn by HPSS to optimize its data transfers. By no means is this a
complete picture of what controls network performance. In fact, the assumption is made
thatthe customer already has the networks optimized by their local network group or has
contacted outside assistance to perform this task. The process described here is to
determine the best user-level values to optimize HPSS performance on an already tuned
network, rather then trying to fix underlying network problems.
Totest the TCP socket performance over a network connection, issue the following on the
receiving node:
% ttcp -r -s -p<port>
where a typical port is 4321. Then issue the following on the transmitting node:
% ttcp -t -s -p<port> <hostname>