Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!mimsy!chris From: chris@mimsy.UUCP (Chris Torek) Newsgroups: comp.bugs.4bsd,comp.unix.wizards Subject: Re: Solution to: Cant access disks on second UDA50 Message-ID: <7942@mimsy.UUCP> Date: Tue, 11-Aug-87 04:29:43 EDT Article-I.D.: mimsy.7942 Posted: Tue Aug 11 04:29:43 1987 Date-Received: Wed, 12-Aug-87 05:09:35 EDT References: <6683@dartvax.UUCP> <6842@dartvax.UUCP> Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742 Lines: 45 Keywords: unibus uda50 Xref: mnetor comp.bugs.4bsd:484 comp.unix.wizards:3639 In article <6842@dartvax.UUCP> steve@dartvax.UUCP (Steve Campbell) writes: >Scott Bradner (harvisr!sob) pointed me in the right direction: >>the 4.3 uda driver has a bug that causes the drives on a 2nd controller >>to appear to go off line under load, any processes that are accessing those >>drives will hang forever. I know nothing of this bug. The 4.3BSD driver does have a `feature' which irritates a microcode bug in some UDA50s, causing the controller itself to hang. This is rare, and current UDA50s do not exhibit the bug at all unless you have a 785 or 8600. Controller hangs are distinguished by the light patterns on one of the two modules in the Unibus box: one of the LEDs stops blinking. There is another bug in 8600s that loses UDA50 interrupts under heavy interrupt load (we get it while using the 4.3BSD rdump on Sun 3s). I do not understand the details, but my driver recovers eventually (at least if you have all your UDA50s on the same Unibus!---there is a bug in the reset code in mscp.c). >Jean Huens (kulcs!jean) got closer: >>... I looked in the uda driver from Ultrix 1.2 and saw they >>start there a timer which calls the udastart routine regularly. Ugh! >In one posting Chris Torek wrote: >>(My first suggestion, of course, was to try my driver....) >Well, I hate a smart aleck, especially one who turns out to be right. Shall I make a point of being wrong on occasion? :-) >Chris's driver prints some identification information at boottime, >including the following from my machine: > Aug 9 12:34:56 libdev vmunix: uda0: version 5 model 6 > ... > Aug 9 12:34:56 libdev vmunix: uda1: version 4 model 6 >Is that different version number significant to this problem? I am not sure what is different between versions 4 and 5; version 3 still exhibits the Get Unit Status hang bug on 780s. We still have some version 4 controllers here, and they work fine. Of course I *am* using my driver.... -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690) Domain: chris@mimsy.umd.edu Path: seismo!mimsy!chris