Re: serious networking (em) performance (ggate and NFS) problem

From: Chuck Swiger <cswiger_at_mac.com>
Date: Wed, 17 Nov 2004 19:57:27 -0500
Wilkinson, Alex wrote:
> ping only tests latency *not* throughput. So it is not really a good test.

You can utilize a decent amount of a 100Mbs link via ping:

42-sec# time ping -q -c 10240 -i 0.00001 -s 1004 cube
PING cube.local (192.168.1.6): 1004 data bytes

--- cube.local ping statistics ---
10240 packets transmitted, 10240 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.455/0.793/4.491/0.418 ms
1.48s real  0.05s user  0.60s system  43%

...which works out to about 7MB/s.  Hmph.  I should have mentioned in my 
previous message that that one ought to do something like:

	sysctl -w net.inet.icmp.icmplim=10000   # or zero, maybe?

...as well, or else ping will be limited to some ~250 pps.  It would be 
interesting for Emanuel to try ping -s with a bigger value suitable to fill 
jumbo frames.

-- 
-Chuck

PS: I just tested several varieties of ping until I got a:

    ping: sendto: No buffer space available

...so I perhaps I need do some additional tuning, myself.  :-)
Received on Wed Nov 17 2004 - 23:58:01 UTC

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