From owner-freebsd-questions@FreeBSD.ORG Thu Mar 19 17:55:31 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2315A10656C9 for ; Thu, 19 Mar 2009 17:55:31 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from asmtpout017.mac.com (asmtpout017.mac.com [17.148.16.92]) by mx1.freebsd.org (Postfix) with ESMTP id 5CC968FC20 for ; Thu, 19 Mar 2009 17:55:29 +0000 (UTC) (envelope-from cswiger@mac.com) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Received: from cswiger1.apple.com ([17.227.140.124]) by asmtp017.mac.com (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTPSA id <0KGR009ACLSFWY00@asmtp017.mac.com> for freebsd-questions@freebsd.org; Thu, 19 Mar 2009 10:55:27 -0700 (PDT) Message-id: <209E15D1-EAB2-476F-A802-CF8577492919@mac.com> From: Chuck Swiger To: Jaime In-reply-to: Date: Thu, 19 Mar 2009 10:55:27 -0700 References: X-Mailer: Apple Mail (2.930.3) Cc: freebsd-questions@freebsd.org Subject: Re: Formatting a tape? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Mar 2009 17:55:32 -0000 On Mar 19, 2009, at 9:15 AM, Jaime wrote: > I have a DLT tape drive in a FreeBSD system. With one of the tapes, I > can get "tar -cvpf /dev/sa0 -C / ." to work. With all the other > tapes, I can't. > > Is there some kind of formatting process that I need to do? I tried > "mt fsf 1" from this page: What's the SCSI controller that you're using, and which version of the OS are you running? What's "mt status" say? Can you try "mt blocksize 0", "mt rewind", "mt weof 2", "mt rewind" and then retry tar? Try changing your blocksize via tar's -b flag to 32, 64, 126, or 128 blocks. FreeBSD doesn't expose enabling/disabling hardware compression or tuning compression levels via the device name used (ala Solaris' /dev/rmt/0ubn for example), so you'll need to look to "mt blocksize" and "mt comp" to adjust, otherwise you'll get whatever default behavior the device is set to. In most cases, the device will want a fairly large blocksize in order to keep streaming the tape. (I've used both Quantum DLT and sDLT drives with FreeBSD 5.x & 6.x on various Adaptec & LSI MegaRAID SCSI controllers-- mostly Dell, some HP boxen....) Regards, -- -Chuck