Date: Sat, 27 Jul 1996 11:56:05 -0400 (EDT) From: Peter Dufault <dufault@hda.com> To: grog@freefall.freebsd.org (Greg Lehey) Cc: julian@whistle.com, scsi@freefall.freebsd.org Subject: Re: Setting disk sector size? Message-ID: <199607271556.LAA00226@hda.com> In-Reply-To: <199607271514.IAA13074@freefall.freebsd.org> from "Greg Lehey" at Jul 27, 96 08:14:30 am
next in thread | previous in thread | raw e-mail | index | archive | help
> > > > A friend of mine just turned up with a Tandem disk drive (looks for > > > all the world like an IBM :-) which has 514 byte sectors. He also has > > > another one with 516 byte sectors. By all accounts we can change that > > > to 512 with 'scsi -m 3 -p 3 -e', except that the driver gets all > > > uptight about the 514 byte sectors and doesn't get as far as reading > > > the mode page. scsiformat can report the format, so there must be > > > some way to do read the information, and I suspect there's also a way > > > to set it. Does anybody have any ideas? > > > > compile a krnrel without that test in sd.c > > and use that to change the setup.. > > > > > I tried that before I sent the message. It hangs (OK, to be more > specific, it times out). I think that the problem is that scsi tries > to access the disk before it reads the mode page. scsiformat issues a > direct scsi command, so I assume that I could issue a write command > and write it back. Unfortunately, I'm on vacation at the moment, and > I don't have any documentation with me. Use the control device for the disk - it will bypass normal processing and all you can do is issue ioctl's against it. The control device is the one with the crazy minor number: > crw------- 1 root wheel 13, 536870912 Jan 10 1996 /dev/rsd0.ctl You should be able to issue the mode page editing and format commands against that device. -- Peter Dufault Real-Time Machine Control and Simulation HD Associates, Inc. Voice: 508 433 6936 dufault@hda.com Fax: 508 433 5267
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199607271556.LAA00226>