From owner-freebsd-questions@FreeBSD.ORG Wed Apr 20 14:10:03 2005 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6709016A4CE for ; Wed, 20 Apr 2005 14:10:03 +0000 (GMT) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id EBE1A43D3F for ; Wed, 20 Apr 2005 14:10:02 +0000 (GMT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.13.1/8.13.3) id j3KEA23l062762; Wed, 20 Apr 2005 09:10:02 -0500 (CDT) (envelope-from dan) Date: Wed, 20 Apr 2005 09:10:02 -0500 From: Dan Nelson To: Konrad Heuer Message-ID: <20050420141002.GC29613@dan.emsphone.com> References: <20050420090231.R37022@gwdu60.gwdg.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050420090231.R37022@gwdu60.gwdg.de> X-OS: FreeBSD 5.4-PRERELEASE X-message-flag: Outlook Error User-Agent: Mutt/1.5.8i cc: freebsd-questions@freebsd.org Subject: Re: DLT tape / no streaming X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Apr 2005 14:10:03 -0000 In the last episode (Apr 20), Konrad Heuer said: > I use a Benchmark DLT tape drive to backup data on my DELL PowerEdge > 2650 system; syslog says: > > Apr 20 09:09:02 gwdu111 /kernel: sa0 at ahc0 bus 0 target 6 lun 0 > Apr 20 09:09:02 gwdu111 /kernel: sa0: Removable Sequential Access SCSI-2 device > Apr 20 09:09:02 gwdu111 /kernel: sa0: 20.000MB/s transfers (10.000MHz, offset 15, 16bit) > > The problem I see is that data flow is not steadily streaming; the > tape drive is operating in start-stop-mode. What blocksize are you using? If you're just using tar, the default of 10k is too small. Try 64k ("tar cvb 128 /usr", for example). -- Dan Nelson dnelson@allantgroup.com