Cdrom Problem

[<@RIVERSIDE.SCRC.Symbolics.COM:rsk@SAMSON.CADR.AMIS.COM>]

    Date: Tue, 15 Jun 1993 13:31 PDT
    From: Barry Margolin <barmar@Think.COM>
	Date: Tue, 15 Jun 1993 14:35 EDT
	From: jbarnett@charming.nrtc.northrop.com
	Restoring world from cdrom mounted on a sun server works like a charm
	for 3670 and 3640 using copy file (symbolics recommended procedure).
	Seems to run ~100 times slower on 3650 -- in fact, not enough time in a
	day to let it complete.  Eventually pops up a restart menu: longer timeout,
	retry connection, etc.

	Symbolics tried swapping io board, paddle, and processor.  Tried swapping
	ethernet connection with one of the machines that works okay.  Nothing
	helps.  Any known problems with 3650 in regards to this?  The only thing
	I can think of is that NSF is sending a lot of long packets and the 3650
	has a slow(?) fep.

    Yes.  The problem is that the default read size is 8K, and this is
    fragmented into 6 IP packets sent in rapid succession.  Unfortunately, a
    G-machine can only read a couple of them, so the reassembly fails and
    the Lispm eventually has to request a retransmission.  Of course, this
    also fails, and so on.

    Ths solution is to set NFS:*LOCAL-SUBNET-TRANSFER-SIZE* and
    NFS:*LOCAL-NETWORK-TRANSFER-SIZE* to something the Lispm can handle.   I
    use 1024 and it works OK.

Wow!  This solves a problem we've been having forever with a 3620
talking NFS to a Sun.

						    barmar