hb@lln-cs.UUCP (Hubert Broze) (08/01/88)
In the past (augustus 87), I read in the NEWS (comp.unix.questions), that some people have encountered some problems on a MicrovaxII with 2 DEQNA's on Mt-Xinu 4.3. I have just configured my MicrovaxII as a gateway machine forfor TCP/IP with 2 DEQNA's and I have the following problem: when the gateway is active, it runs fine but all other activites (on local disks) are impossible. It would like to meet (by mail) people who have some experiences with the problem mentionned above. Thanks in advance, H. Broze System Manager E-mail: prlb2!lln-cs!hb (Belgium)
jpd@eecs.nwu.edu (J. Phillip Draughon) (08/02/88)
In article <870@lln-cs.UUCP> hb@lln-cs.UUCP writes: > In the past (augustus 87), I read in the NEWS (comp.unix.questions), > that some people have encountered some problems on a MicrovaxII with 2 DEQNA's on > Mt-Xinu 4.3. Yup...that was us. > I have just configured my MicrovaxII as a gateway machine forfor TCP/IP > with 2 DEQNA's and I have the following problem: when the gateway is > active, it runs fine but all other activites (on local disks) are impossible. That is exactly the behavior that we noticed. You can have either DEQNA running and still have other things going on, but not both. When we were running both DEQNAs everything would run find for about 20 minutes, and then WHAM!--anything attempting to use the disk would get hung. We experienced the same problem using 4.3BSD. We eventually fell back to Ultrix 1.2, and the problem did not surface again. We now have a cisco router to do the job for us, and our MicroVAX II is running Mt Xinu again. -- Phil Draughon Academic Computing and Network Services Northwestern University
lamaster@ames.arc.nasa.gov (Hugh LaMaster) (08/03/88)
In article <3880005@eecs.nwu.edu> jpd@eecs.nwu.edu (J. Phillip Draughon) writes: >> with 2 DEQNA's and I have the following problem: when the gateway is >> active, it runs fine but all other activites (on local disks) are impossible. >That is exactly the behavior that we noticed. You can have either It sounds like it might be a bus priority problem. I am not sure if DEQNA's have some kind of "autothrottle" or "adaptive DMA" or whatever, but I know that sometimes two such controllers can effectively lock out everything else on the bus. You might check and see if the DEQNA can be configured in two modes, and try the other one. At least with Unibus devices, the solution is another Unibus. -- Hugh LaMaster, m/s 233-9, UUCP ames!lamaster NASA Ames Research Center ARPA lamaster@ames.arc.nasa.gov Moffett Field, CA 94035 Phone: (415)694-6117
chris@mimsy.UUCP (Chris Torek) (08/03/88)
As another data point, we have a MicroVax II running 4.3BSD-tahoe, with two DEQNAs and one RD53. It is used as a gateway and is largely left alone, but has nightly disk activity, and is occasionally used for small tasks. It never hangs. (Perhaps the problem is in the old UDA50 driver.) -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris
eli@spdcc.COM (Steve Elias) (08/04/88)
DEQNAs are recommended to be at the highest priority bus positions to ensure that no receptions are lost. Two of them can use up 2*10Mb/s*1B/8b = 2.5MByte/sec of the uVAX-II's Q-Bus (a majority of it). Of course, the Ethernets are not 100% loaded, but there is some DMA overhead that can help make up for it. When you buy the fastest Q-Bus Ethernet adapter, you have to make these sacrifices... ... the above reply is from my manager, an ex-DEC employee ... steve elias Chipcom Corporation.
mostardi@ux1.lbl.gov (David Mostardi) (08/09/88)
Is anyone out there using an Ungermann-Bass ACCESS-ONE box with twisted-pair over Ethernet? I am considering this product for my installation and would appreciate any feedback. David Mostardi Systems Administrator, MSRI, Berkeley CA mostardi@ux1.lbl.gov "Guess what Dad! Those chocolate diskettes fit right into your computer, no problem!"
lee@turing.unm.edu (Lee Ward) (08/11/88)
In article <870@lln-cs.UUCP> hb@lln-cs.UUCP (Hubert Broze) writes: >In the past (augustus 87), I read in the NEWS (comp.unix.questions), >that some people have encountered some problems on a MicrovaxII with 2 DEQNA's on >Mt-Xinu 4.3. I have just configured my MicrovaxII as a gateway machine forfor TCP/IP >with 2 DEQNA's and I have the following problem: when the gateway is >active, it runs fine but all other activites (on local disks) are impossible. > Wow, an exact description of the problem we have been having for about a year. Your problem is more extensive than you know. 1) The splnet() in your kernel could be wrong. Though if you have gotten to the "my disk quits responding" part it is most likely right. Just in case here is a diff of /sys/vax/inline/langpats.c RCS file: RCS/langpats.c,v retrieving revision 1.1 diff -r1.1 langpats.c 41c41 < mtpr $0x16,$18\n" }, --- > mtpr $0x17,$18\n" }, 2) You can REALLY aggravate the problem if you have two disk controllers present. When IO activity gets heavy the system freezes. If you have a systat (:v) running you will see your load go up, up, up and nobody but the systat will come on the run queue. A kludge is to put a timeout in your driver that will kick the controllers. If you do this and try to run both DEQNA's your disk controllers will get kicked alot but, alas, it still won't work. I have a program that I can send to you that will freeze your system every time. I won't post it as some malicious user might want to try it too. If ANYONE can get two DEQNA's going under MT-XINU please let me know too. We're about to put up Ultr*x to solve the problem. We have had to move 20 machines over to the campus net and they page like mad. Our floor loop is entirely useless until we can bring the second DEQNA on line. --Lee (Ward)
ellis@godot.psc.edu (James Ellis) (08/13/88)
In article <1169@unmvax.unm.edu> lee@turing.unm.edu (Lee Ward) writes: >In article <870@lln-cs.UUCP> hb@lln-cs.UUCP (Hubert Broze) writes: >>In the past (augustus 87), I read in the NEWS (comp.unix.questions), >>that some people have encountered some problems on a MicrovaxII with 2 DEQNA's on >>Mt-Xinu 4.3. I have just configured my MicrovaxII as a gateway machine forfor TCP/IP >>with 2 DEQNA's and I have the following problem: when the gateway is >>active, it runs fine but all other activites (on local disks) are impossible. >> > When this happened to us the problem turned out to be that the ethernet driver was reserving too many receive buffers. Mike Karels suggested lowering NRCV. (NRCV is in vaxif/if_qe.c.) We dropped it from 25 to 15 on our systems and have had several (busy) such gateways working fine since. This has worked on both UCB 4.3 and Mt. Xinu. Jim Ellis Pittsburgh Supercomputing Center