3c59x: recurring transmit errors

Ravi Swamy ravi@rtp.mea.com
Tue Jul 28 15:49:18 1998

On Tue, 28 Jul 1998, Dan Stromberg wrote:

> Ravi Swamy wrote:
> > Your friend is somewhat correct on Linux NFS writes.  Linux NFS writes
> > to another Linux box are quite fast.  I've gotten over 2.5MB/s which I'm
> > quite happy with.  Linux NFS writes to a Solaris server are horrendous.
> > I can't even get 300kB/s.  No I'm not assigning blame, for all I know it
> > could be Solaris but I've seen at least 3 people verify the same behavior
> > and none knew how to "fix" it.  No, changing the rsize and wsize did not
> > help at all.  Maybe 5% but that's it.  I've tried 1k, 2k, 4k, 8k, 16k, 32k.
> In my case, using an 8k rsize and wsize makes a VERY LARGE difference -
> it yields a very nice performance improvement.

Even with 8k rsize,wsize I only get around 300kB/s.  This is on a PPro 200 w/
a 3c905 on a 100Mb hub.  There is very little traffic on the hub, I can
run the test at 1am and see very little difference.

In contrast I can take a 4 year old SPARCstation 5 running Solaris 2.5.1 w/
a 10Mb link going to the same remote Solaris NFS server and get 1.03MB/s.
This is copying the exact same file from the Linux box to Solaris server
and a lowly 10Mb Solaris box to the Solaris server.
> In fact, I'd say the current default block size is a poor choice, and
> should be raised to 8k, like on other unixes.

I just don't see it helping much.  It does seem to speed things up by 
maybe 25% but I need a 10X  increase.  My 300KB/s should be 3MB/s.

The Suns on the 100Mb hub can easily get 5 or 6 MB/s.
> IMO, the slowness problem is in the linux NFS code, because solaris,
> irix and osf/1 (and possibly others) can read/write to/from each other
> quickly.

I've never seen it explained.  I always hear people say "change the rsize/wsize"but it is just a small improvement.  I can ftp files to and from Linux<->Solaris
and get almost 8MB/s but NFS writes crawl...