From owner-freebsd-scsi@FreeBSD.ORG Sun Jul 31 16:32:25 2005 Return-Path: X-Original-To: freebsd-scsi@freebsd.org Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4AEBD16A41F for ; Sun, 31 Jul 2005 16:32:25 +0000 (GMT) (envelope-from jhs@flat.berklix.net) Received: from tower.berklix.org (tower.berklix.org [83.236.223.114]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6B3A743D45 for ; Sun, 31 Jul 2005 16:32:23 +0000 (GMT) (envelope-from jhs@flat.berklix.net) Received: from js.berklix.net (p549A4BA2.dip.t-dialin.net [84.154.75.162]) (authenticated bits=0) by tower.berklix.org (8.12.9p2/8.12.9) with ESMTP id j6VGWIxr096576; Sun, 31 Jul 2005 18:32:19 +0200 (CEST) (envelope-from jhs@flat.berklix.net) Received: from fire.jhs.private (fire.jhs.private [192.168.91.41]) by js.berklix.net (8.12.11/8.12.11) with ESMTP id j6VGW93N002544; Sun, 31 Jul 2005 18:32:12 +0200 (CEST) (envelope-from jhs@flat.berklix.net) Received: from fire.jhs.private (localhost.jhs.private [127.0.0.1]) by fire.jhs.private (8.13.1/8.13.1) with ESMTP id j6VGW9OM054232; Sun, 31 Jul 2005 18:32:09 +0200 (CEST) (envelope-from jhs@fire.jhs.private) Message-Id: <200507311632.j6VGW9OM054232@fire.jhs.private> To: Frank Mancuso In-Reply-To: Message from Frank Mancuso of "Sun, 31 Jul 2005 11:43:24 EDT." Date: Sun, 31 Jul 2005 18:32:09 +0200 From: "Julian H. Stacey" Cc: freebsd-scsi@freebsd.org Subject: Re: scsi tape drive slow in freebsd X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 31 Jul 2005 16:32:25 -0000 Frank Mancuso wrote: > hello there I have a scsi tape drive which is made by seagate python. > It is a scsi 2. normally in linux or windows it takes about 2 hours > and 30 mins to restore or backup. I just installed freebsd 4.11 and I > started to restore and it has been running for more then 10 hours .. > > this is my dmesg > > ahc0: port 0xe800-0xe8ff mem 0xe1811000-0xe1811fff irq 11 at device 12.0 on pci0 > aic7860: Ultra Single Channel A, SCSI Id=7, 3/253 SCBs > Waiting 15 seconds for SCSI devices to settle > sa0: Removable Sequential Access SCSI-2 device > > I had to recompile the kernel to support my dual P3 I was wondering if > maybe I had to add something in the kernel to speed this up.. > > thanks. perhaps mt blocksize 512 or mt blocksize 0 I used to see vast slow down if reader wasnt reading how how the writer wrote it. Also think blocking with tar if that's what your using eg -b 10k or 60k or whatever Your ear should tell you if it's streaming or stop starting. Ref man mt -- Julian Stacey Consultant Systems Engineer, Munich. http://berklix.com Mail in Ascii (Html = Spam). Ihr Rauch = mein allergischer Kopfschmerz.