From owner-freebsd-questions@FreeBSD.ORG Wed Jan 28 20:23:54 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 117DF106564A for ; Wed, 28 Jan 2009 20:23:54 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: from email1.allantgroup.com (email1.emsphone.com [199.67.51.115]) by mx1.freebsd.org (Postfix) with ESMTP id BE76E8FC08 for ; Wed, 28 Jan 2009 20:23:53 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (dan-a.emsphone.com [199.67.51.107]) by email1.allantgroup.com (8.14.0/8.14.0) with ESMTP id n0SKNqYM000477 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 28 Jan 2009 14:23:53 -0600 (CST) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (smmsp@localhost [127.0.0.1]) by dan.emsphone.com (8.14.3/8.14.3) with ESMTP id n0SKNqmF096271 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 28 Jan 2009 14:23:52 -0600 (CST) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.3/8.14.3/Submit) id n0SKNouc096252; Wed, 28 Jan 2009 14:23:50 -0600 (CST) (envelope-from dan) Date: Wed, 28 Jan 2009 14:23:50 -0600 From: Dan Nelson To: Jaime Message-ID: <20090128202349.GD63837@dan.emsphone.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-OS: FreeBSD 7.1-STABLE User-Agent: Mutt/1.5.18 (2008-05-17) X-Virus-Scanned: ClamAV version 0.94.1, clamav-milter version 0.94.1 on email1.allantgroup.com X-Virus-Status: Clean X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0.2 (email1.allantgroup.com [199.67.51.78]); Wed, 28 Jan 2009 14:23:53 -0600 (CST) X-Scanned-By: MIMEDefang 2.45 Cc: freebsd-questions@freebsd.org Subject: Re: Quantum tape drive 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: Wed, 28 Jan 2009 20:23:54 -0000 In the last episode (Jan 28), Jaime said: > I am trying to replace an older DLT tape drive (which doesn't like to > eject tapes any more) with a new Quantum DLT-4 drive. Its connected > by internal SCSI and seems to be set up right. But after DAYS of > running a tar command, its still not done backing up 60GB. The old > drive could backup 70-80GB in about 7 hours. > > Any suggestions? > > /usr/bin/tar -cvpX /usr/local/etc/backups/skiplist-relative.txt -f /dev/sa0 -C / . If nothing else, I suggest bumping up your blocksize. The default for tar (10k) is pretty small for modern tape drives. Try -b 128 (for a 64k block size). Another optimization would be to put a buffering program in between tar and your tape drive to decouple disk reads from tape writes. misc/team, misc/buffer, and misc/cstream in ports are good for this. -- Dan Nelson dnelson@allantgroup.com