From owner-freebsd-scsi Mon Aug 23 7:30:32 1999 Delivered-To: freebsd-scsi@freebsd.org Received: from feral.com (feral.com [192.67.166.1]) by hub.freebsd.org (Postfix) with ESMTP id 735B214BCE for ; Mon, 23 Aug 1999 07:30:26 -0700 (PDT) (envelope-from mjacob@feral.com) Received: from semuta.feral.com (semuta [192.67.166.70]) by feral.com (8.8.7/8.8.7) with ESMTP id HAA13592; Mon, 23 Aug 1999 07:26:43 -0700 Date: Mon, 23 Aug 1999 07:26:41 -0700 (PDT) From: Matthew Jacob Reply-To: mjacob@feral.com To: Christian Weisgerber Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: tape: can't set blocksize on Wangtek In-Reply-To: <7pp7h0$18d$1@bigeye.rhein-neckar.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > Christian Weisgerber wrote: > > > 4.0-CURRENT from a few days ago, QIC-1000 tape drive: > > sa0: Removable Sequential Access SCSI-CCS device > > Okay, I think I'm seeing a pattern here. > It seems I can successfully change the block size if there is no > tape inserted. (Or after an "mt offline", which presumably amounts to > the same thing even if the tape is still physically in the drive.) Yes- that's likely with a fixed blocksize device that bases what size it is set to on what the tape can support. This may be complicated by the fake variable mode that some drives support. > > Changing the block size after a tape has been inserted but not yet > read from works sometimes. No recognizable pattern yet. Changing > the block size after the tape has been read from fails reliably. Yes- and this may get worse- I'm about to commit changes that will do a test read at tape mount time in order to determine existing blocksize and tape density (or, rather, force the drive to set these values by getting it to do a media access). There are two problems you've reported- one where you have trouble changing blocksize and the other where reading the tape gives you NULLs and other things, etc.. The former problem you've tripped over while trying to set 'variable' mode (at my request) to see if your tape is readable in fake 'variable' mode. I'm not sure what to tell you to do at this point. What mode was this tape *written* under? -matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message