From owner-freebsd-scsi Thu Mar 11 8:20:52 1999 Delivered-To: freebsd-scsi@freebsd.org Received: from TomQNX.tomqnx.com (cpu2745.adsl.bellglobal.com [207.236.55.214]) by hub.freebsd.org (Postfix) with ESMTP id 087D7151BD for ; Thu, 11 Mar 1999 08:20:44 -0800 (PST) (envelope-from tom@tomqnx.com) Received: by TomQNX.tomqnx.com (Smail3.2 #1) id m10L8Bw-000I0zC; Thu, 11 Mar 1999 11:20:12 -0500 (EST) Message-Id: From: tom@tomqnx.com (Tom Torrance at home) Subject: Re: 3.1-STABLE: nrsa0 T4000 doesn't honor "no rewind"? SCSI errs in logs In-Reply-To: from Matthew Jacob at "Mar 10, 1999 10:23:42 am" To: mjacob@feral.com Date: Thu, 11 Mar 1999 11:20:12 -0500 (EST) Cc: tom@tomqnx.com, chris@shenton.org, scsi@freebsd.org X-Mailer: ELM [version 2.4ME+ PL43 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1547 Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hello, Matt: I'd like to submit a somewhat more positive suggestion for your consideration. I don't object to positive action to prevent data corruption, I just don't like the idea of unilateral action by the driver that affects tape positioning. How about the following? 1) Receive the error. 2) Verify that it is not a harmless device quirk. 3) Map the error back to the application for action. 4) Until the application or the operator does something positive to re-establish positioning, greet further attempts to write with a media write-protected error. 5) It might be possible to allow the tape operator a mechanism to turn off the condition (the 'ignore' option) in some harmless way. Perhaps an 'mt status'? There might be some actions that would/should be allowable, like writing tape marks - you would be much better qualified to judge those. On the face of it, though, this approach might satisfy your concerns (and mine). The downside is all the queries you might receive from people puzzled as to why they would suddenly get a media write- protected error from a tape that they have been happily writing to... Good explanations/instructions in the error logs would help in this regard. Particular care should be taken that only the problem device/app is affected for systems with multiple tape drives. Obviously something like this would have to be properly tested with the most common backup systems to ensure that there is not some potentially harmful application interaction. What do you think? Cheers, Tom To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message