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 Message-ID: <19970624232034.XM49539@uriah.heep.sax.de> In-Reply-To: <199706241950.MAA02518@hub.freebsd.org>; from Bill Fenner on Jun 24, 1997 12:50:01 -0700 References: <199706241950.MAA02518@hub.freebsd.org>
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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. ;-)
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