Messages in this thread | | | Date | Wed, 24 Jan 2001 10:19:52 -0800 | From | "H . J . Lu" <> | Subject | Re: [NFS] [CFT] Improved RPC congestion handling for 2.4.0 (and 2.2.18) |
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On Mon, Jan 22, 2001 at 03:36:38PM -0800, H . J . Lu wrote: > On Tue, Jan 23, 2001 at 12:00:29AM +0100, Trond Myklebust wrote: > > >>>>> " " == H J Lu <hjl@valinux.com> writes: > > > > > I got a report which indicates it may not be a good idea, > > > especially for UDP. Suppose you have a lousy LAN or NFS UDP > > > server for whatever reason, some NFS/UDP packets may get lost > > > very easily while a ping request may get through. In that case, > > > the rpc ping may slow down the NFS client over UDP > > > significantly. > > > > Hi HJ, > > > > Could you clarify this? Don't forget that we only send the ping after > > a major timeout (usually after 3 or more resends). > > > > IOW: If the ping gets through, then it'll have cost us 1 RPC request, > > which is hardly a major contribution when talking about timescales of > > the order of 5 seconds which is what that major timeout will have cost > > (Don't forget that RPC timeout values increase geometrically). > > > > Michael Kriss <kriss@fnal.gov> is having this problem. I think this > problem may be very specific to his network setup. I couldn't duplicate > his problem. My guess is for his case, every ping sent is a loss of > a potential working retry packet. He is using Solaris NFS sever with > Linux client. I had an impression that packets from Solaris NFS server > was dropped quite often. I don't know what happened. >
I believe it is a false alarm. It turned out that the interface was not in the full duplex mode. After turning on autonego on switch, everything seems fine now. Sorry for that.
-- H.J. Lu (hjl@valinux.com) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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