[Beowulf] NFS Read Errors
Michael H. Frese
Michael.Frese at NumerEx.com
Fri Dec 7 12:28:14 EST 2007
An interesting suggestion. I'll look into it. Thanks.
At 09:57 AM 12/7/2007, Skylar Thompson wrote:
>Michael H. Frese wrote:
> > Fourth, with ttcp over tcp, I found that the troubled machine could
> > send 800 MB in about 20 seconds -- the wire speed for those 32-bit PCI
> > slots as tested by netpipe. However, if I used ttcp over udp, I
> > couldn't reliably send even ten 8192-byte blocks! Successive sends
> > and receives would receive 3, or 1, or 5 blocks. Don't ask me how
> > these two facts are compatible. I don't know.
>This sounds like it could be a flow control issue. TCP does its own flow
>control, but UDP doesn't. Some Ethernet switches do IEEE 802.3x, which
>might help your UDP performance.
>-- Skylar Thompson (skylar at cs.earlham.edu)
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