Path: utzoo!utgpu!watserv1!watmath!att!linac!uwm.edu!cs.utexas.edu!sun-barr!newstop!exodus!terra.Eng.Sun.COM!brent From: brent@terra.Eng.Sun.COM (Brent Callaghan) Newsgroups: comp.protocols.nfs Subject: Re: Summary: NFS over links slower than 10 Mbit/sec Message-ID: <7645@exodus.Eng.Sun.COM> Date: 8 Feb 91 07:32:12 GMT References: <1991Feb5.031603.2969@amd.com> <7371@exodus.Eng.Sun.COM> Sender: news@exodus.Eng.Sun.COM Lines: 23 In article , meissner@osf.org (Michael Meissner) writes: > Always set UDP checksums, even over ethernet. Back in a previous > life, I was on a local ethernet where I could not reliably build GCC > without one .o being corrupted. Whomever in Sun made the choice not > to checksum NFS packets should have his/her/its head examined.... I too have heard of instances where NFS data has been corrupted by bad ethernet hardware or flakey routers that drop a bit now and then. When NFS first shipped on Suns, we had just one or two MIPS of CPU to play with. UDP checksumming was a significant overhead. Bit errors on most ether networks was (and is) very low. Now, with most workstations provide 10 - 30 MIPS, the performance impact of checksumming is not an issue - particularly when implemented as part of a memory copy operation. BTW: you can turn on checksums just by setting udp_cksum to 1. -- Made in New Zealand --> Brent Callaghan @ Sun Microsystems Email: brent@Eng.Sun.COM phone: (415) 336 1051