From owner-freebsd-bugs Tue Jun 24 16:22:18 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id QAA13136 for bugs-outgoing; Tue, 24 Jun 1997 16:22:18 -0700 (PDT) Received: from sax.sax.de (sax.sax.de [193.175.26.33]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id QAA13128 for ; Tue, 24 Jun 1997 16:22:12 -0700 (PDT) Received: (from uucp@localhost) by sax.sax.de (8.6.12/8.6.12-s1) with UUCP id BAA27601; Wed, 25 Jun 1997 01:21:58 +0200 Received: (from j@localhost) by uriah.heep.sax.de (8.8.5/8.8.5) id XAA03660; Tue, 24 Jun 1997 23:20:34 +0200 (MET DST) Message-ID: <19970624232034.XM49539@uriah.heep.sax.de> Date: Tue, 24 Jun 1997 23:20:34 +0200 From: j@uriah.heep.sax.de (J Wunsch) To: fenner@parc.xerox.com (Bill Fenner) Cc: freebsd-bugs@hub.freebsd.org Subject: Re: bin/3942: mmap fails on large file on CDROM References: <199706241950.MAA02518@hub.freebsd.org> X-Mailer: Mutt 0.60_p2-3,5,8-9 Mime-Version: 1.0 X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) In-Reply-To: <199706241950.MAA02518@hub.freebsd.org>; from Bill Fenner on Jun 24, 1997 12:50:01 -0700 Sender: owner-bugs@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk As Bill Fenner wrote: > Jun 24 19:26:16 sundae /kernel: cd0(ncr0:6:0): MEDIUM ERROR info:12e73 asc:15,0 Random positioning error > Jun 24 19:26:16 sundae /kernel: vm_fault: pager input (probably hardware) error, PID 16521 failure That explains it. > However, dd'ing the same file succeeds at reading the block in > question, so I'm not sure that I believe there's a medium error in the > file. It is, unless your drive is lying. It's not surprising that the behaviour for a dd is different, as the error message says, it's a random positioning error. So for the tail, it's going to move the drive's head to a different spot, and it simply doesn't find the expected data then. For the dd command, the head smoothly follows the CD track, thus finds the desired data. That's either a failing drive (positioning not working), or an incompatibility for the drive/medium combo. I think you can close this PR. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)