Network Slowdowns?

[Oliver Fromme]

Jamie wrote:
 > So far, no errors but file copies are still slow. Makes me suspect the
 > underrun errors weren't related?

I also think they're unrelated.

 > About ~ 1 mb/sec across a 100mbs ethernet connection. Correct me if I'm
 > wrong, but shouldn't this be closer to 5-10 megabytes/sec,

Right.

Everything configured to the optimum (and good hardware),
you can get slightly more than 10 MByte/s through Fast-
Ethernet.

 > The ifconfig up/down trick doesn't seem to make a difference at this point. 

Are you sure that there is no duplex mismatch?  Are both
sides of the cable running at full-duplex?  (Under BSD,
ifconfig tells you.)  Are there any collisions or Ierrs/
Oerrs reported by "netstat -i" on either side of the
connection?

 > NFS still locks up as well. (I just did a cat /dev/zero >$NFS_MOUNTED_PATH/zero) 
 > and it (NFS) froze) 

What NFS parameters are you using?  v2, v3, UDP, TCP,
hard/soft, intr, ...

If you're running NFS over UDP, try switching to TCP (if
the other side supports it).  NFS over UDP seems to be
very sensitive to packet loss, while TCP doesn't have that
much of a problem with that.

(Of course, you shouldn't have packet loss in the first
place.  But it's worth a try.)

 > Wish I had used dd instead... can't seem to CTRL-C the cat process now. :-/

What makes you think you could abort dd, when you can't
abort cat?  My guess is that the NFS mount is dead, which
means that processes which try to access it hang in the
"D" state (disk wait).  ps will confirm that.  It doesn't
matter whether it's cat or dd.

If your NFS mount has the "intr" flag, you should be able
to Ctrl-C them, though.

Best regards
   Oliver

-- 
Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd

Any opinions expressed in this message may be personal to the author
and may not necessarily reflect the opinions of secnetix in any way.