From owner-freebsd-scsi Wed Jan 26 16:50:55 2000 Delivered-To: freebsd-scsi@freebsd.org Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by hub.freebsd.org (Postfix) with ESMTP id 2EA6414E85 for ; Wed, 26 Jan 2000 16:50:50 -0800 (PST) (envelope-from grog@freebie.lemis.com) Received: (from grog@localhost) by freebie.lemis.com (8.9.3/8.9.0) id KAA31960; Thu, 27 Jan 2000 10:55:11 +1030 (CST) Date: Thu, 27 Jan 2000 10:55:10 +1030 From: Greg Lehey To: Matthew Jacob Cc: Palle Girgensohn , "Louis A. Mamakos" , freebsd-scsi@FreeBSD.ORG Subject: Re: cannot mt retension (seagate python) Message-ID: <20000127105510.H53307@freebie.lemis.com> References: <20000127092913.C53307@freebie.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0pre2i In-Reply-To: WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Wednesday, 26 January 2000 at 16:17:43 -0800, Matt Jacob wrote: > >> On Wednesday, 26 January 2000 at 14:33:37 -0800, Matt Jacob wrote: >>>>> Hmm... my tapes sometimes jam. I though a retension would help, but >>>>> I guess I have to calculate on a certain amount of failure. >>>> >>>> No, this is a problem with your drive. This shouldn't happen, and >>>> it's a bad sign. >>> >>> This happens with some frequency with DAT. Regular head cleaning >>> helps, >> >> That depends on what's causing the jamming. I've never seen any >> relationship between jamming and head cleaning. > > If enough gunk builds up on the heads, the tape lifts off slightly > and starts a roll which can get reverse wrapped around a capstan > roller. I've seen this on other tapes, but not helical scan. By the time this happens on a helical scan tape, I would imagine that the read errors would make it inoperative. I *have* seen serious problems with DDS drives, including jamming, but they have happened about equally with cleaned and uncleaned tapes. Greg -- Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message