IBM High Performance Storage System HPSS, Installation Manual

Page: 131 / 311

...
ccs0
64k 64k On -- --
ccs0 64k 32k On -- --
...
You are looking for the best values possible for each network connection. These values will
be used by HPSS to optimize its data transfers. This example is, by no means, a complete
picture of what controls network performance. In fact, it is assumed that you have already
optimized the networks. The reason for gathering these values is to optimize HPSS
performance on an already tuned network, not to fix underlying network problems.
To test 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>
Note that the ttcp tool is included in the deployment package and is not related to the UNIX
ToolTalk service.
HPSS makes extensive use of a system’s networking capabilities. Therefore, the setting of the
tunable networking parameters for the systems on which the various HPSS servers and clients
will run can have a significant impact on overall system performance.
AIX provides a utility program to display and modify a number of networking parameters.
The utility is
no (Network Options). Refer to the AIX Performance Tuning Guide , for details
of each option and its impact on networking and system performance.
Some options that typically impact performance within an HPSS system environment are:
Table 8. Network Options
Network Option Description
thewall Controls the maximum amount of system
memory that can be used by the system
networking code. A value that is too low can
cause networking requests to be delayed or
denied. The recommendation from AIX
development is to set this value to at least two
times the maximum number of concurrent
connections times the size of the socket
send/receive buffers. The default setting for AIX
4.3.2 and later is the smaller of (1) half the size
of physical memory or (2) 1 GB.
sb_max Controls the maximum size allowed for send and
receive buffers for a socket.
HPSS Installation Guide July 2008
Release 6.2 (Revision 2.0) 131