From owner-freebsd-hackers Wed May 22 05:16:37 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id FAA22744 for hackers-outgoing; Wed, 22 May 1996 05:16:37 -0700 (PDT) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id FAA22739 for ; Wed, 22 May 1996 05:16:33 -0700 (PDT) Received: from msmith@localhost by genesis.atrad.adelaide.edu.au (8.6.12/8.6.9) id WAA04592; Wed, 22 May 1996 22:00:22 +0930 From: Michael Smith Message-Id: <199605221230.WAA04592@genesis.atrad.adelaide.edu.au> Subject: Re: 960501-SNAP: data corruption reading /dev/rwt0 (Wangtek) To: gwk@cray.com Date: Wed, 22 May 1996 22:00:21 +0930 (CST) Cc: freebsd-hackers@freebsd.org In-Reply-To: <199605220939.LAA01849@racer.dkrz.de> from "Georg-W. Koltermann" at May 22, 96 11:39:09 am MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Georg-W. Koltermann stands accused of saying: > > The details are still a bit fuzzy, but maybe someone has seen this > already and can give me a hint before I spend countless hours of > hunting. Here is what I see: Sorry, no 8( > I got an old Wangtek QIC-150 tape device a couple of weeks ago, while > still running 2.1.0-RELEASE on my old (386DX/40, 8MB) machine. It > seemed to work flawlessly. > > One week ago I got a new PC (586/100, 32MB, ASUS T2P4), and tried to > install 960501-SNAP from tape. Turned out most of the files read from > tape were corrupted, so the installation would abort after unpacking > one or two files of the first dist. I switched to the shell on VT4 > and tried to untar the tape manually, then cat | zcat | cpio -itv to > check if I could read the pieces. The tar finished without an error > indication, but typically the zcat would abort readily, so I could > only list a few files from the archive. > > I untarred the same tape a couple of times, trying different block > sizes on the tar command. Eventually (using a blocking count of 16) I > could read the tape without corruption, and could install the snap. This sounds like the interface card isn't talking to the rest of the system very well. Have you tried fiddling with the ISA bus timing? Try increasing the back-to-back IO delay, 8- and 16-bit I/O waitstates, 8- and 16-bit DMA waitstates, etc., anything at all related to timing on the ISA bus. Also make sure the ISA bus clock is around 8MHz. > Now with the snap loaded and running flawlessly, I want to read my > backups from tape (cpio -H crc format), but again I am getting data > corruption. When I look at the files extracted, they look fine up to > a certain point where they just contain binary zeroes. I have again This sounds horribly like it's something getting out of sync. > Any ideas? Put the tape drive back on the 386 and use rmt to talk to it 8) > Georg -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[