copy 150G over 100Mbit

Hendrik Scholz hscholz at
Mon Jun 2 08:32:55 PDT 2003


On Mon, 2 Jun 2003 16:23:17 +0200
Damir Horvat <damir at> wrote:

> I've tryed rsync and cp over NFS. Both came down roughly to 2Gig's per
> hour, which is unacceptable. The only option left (as I see it) is to
> try with cross-over cable.

'systat -vmstat 1' should show the bottleneck as long as it isn't the
network itself.
What kind of NICs do you have? Try enabling IRQ mitigation on them or
other features if supported (ifconfig fxp0 link0 turns on IRQ mitigation
on Intel cards).
IRQ moderation/mitigation lowers the number of interrupts generated by
the network card by bundling (in most cases up to 6 depending on the
FIFO buffer size) interrupts generated by the card. 

Try 'bing' or another network performance measurement tool to determine
the max. network speed possible without paying attention to your

Since you don't care about security you might want to try vsftpd from
the ports. vsftpd supports sendfile() thus eliminating copying data
between memory regions if you card supports the so called zero-copy
features (i.e. can read packet header and body from different buffers).
>From my point of view vsftpd is the fastest ftpd available.


P.S. I'm just gathering some useful information for a FreeBSD network
     performance tuning article.

Hendrik Scholz - <hscholz at> -

Forcast for tonight: Dark.

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