Tune TCP for high speed/large file transfers

[Bit Bucket]

Hi,
I am running Solaris 9 9/05 + latest patches on two V440s with 8GB RAM
each. There is a quad ce card in both (slot 5, 66MHz) and a single
crossover cable connecting the two servers back to back.

I want to maximise the transfer rate between the two servers. The
crossover autonegotiated to 1000Mbps/full.

Using FTP with no mods to TCP tunables I get about 17MB/s transferring
a large urandom file. I tried enabling jumbo frames on both interfaces
but this did not make much difference.

I know there are a number of tcp and ce driver settings to tune, but I
have no experience with this. So if anyone out there has any
experience speeding up back to back network links I would appreciate
the help.

[victorf...@yahoo.com]

Operating on random file is very slow. So maybe the slowness is from
the system itself. Did you try some sequential files?

Victor

[Bit Bucket]

I was testing with a pseudo random file because I want to get a true
idea of the sustained speed to expect. /dev/urandom is a good source
to create a test file because it is not very compressible.

[Greg Andrews]

Bit Bucket <bitbu...@gmail.com> writes:
>Hi,
>I am running Solaris 9 9/05 + latest patches on two V440s with 8GB RAM
>each. There is a quad ce card in both (slot 5, 66MHz) and a single
>crossover cable connecting the two servers back to back.
>
>I want to maximise the transfer rate between the two servers. The
>crossover autonegotiated to 1000Mbps/full.
>
>Using FTP with no mods to TCP tunables I get about 17MB/s transferring
>a large urandom file. I tried enabling jumbo frames on both interfaces
>but this did not make much difference.
>

Don't use FTP to measure network throughput, particularly the stock
Solaris 9 and lower client and server (though the throughput cap may
have been lifted in a patch).

Instead use TTCP.

-Greg
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