From owner-freebsd-questions@FreeBSD.ORG Mon Jul 25 12:20:16 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org 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 D154F16A41F for ; Mon, 25 Jul 2005 12:20:16 +0000 (GMT) (envelope-from ml.freebsd.questions@gmail.com) Received: from wproxy.gmail.com (wproxy.gmail.com [64.233.184.198]) by mx1.FreeBSD.org (Postfix) with ESMTP id E303F43D53 for ; Mon, 25 Jul 2005 12:20:15 +0000 (GMT) (envelope-from ml.freebsd.questions@gmail.com) Received: by wproxy.gmail.com with SMTP id 71so875296wri for ; Mon, 25 Jul 2005 05:20:15 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=bBrwfzpvq1TWM4JAV9Oi1U+2Kvx9xYwV2/ce8YUknj0kSuRvtL02j/xTA0rV7jXMJh2tK5qV+V3YBR+dY9BYlUFKzgXMYbonRpSSjp04SxcCE6t1eluNxoAG3NCvKiGdfYjoD3/Tl1Hmkmt7uB64mNqMU1+to6xVCi0LVud152c= Received: by 10.54.52.55 with SMTP id z55mr2175550wrz; Mon, 25 Jul 2005 05:20:14 -0700 (PDT) Received: by 10.54.76.12 with HTTP; Mon, 25 Jul 2005 05:20:14 -0700 (PDT) Message-ID: <10549b08050725052035362ea8@mail.gmail.com> Date: Mon, 25 Jul 2005 08:20:14 -0400 From: FreeBSD Questions To: freebsd-questions@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Subject: Dump/Tape block question X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: FreeBSD Questions List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Jul 2005 12:20:16 -0000 Sorry if this is a repeat. I posted this on the 21st and never saw it show= up in the mailing list, so I'm assuming nobody ever received it. I have a question about dump and tape blocks. When I do backups, dump tells me it uses a certain number of blocks for that particular backup. I explicitly set my block size to 65K when I do a dump. When I read the SCSI or hardware block location on the tape after the dump, it's nowhere near the same number as what dump said it used. How big is each block? I'd like to know about where on the tape I am when I do an 'mt rdhpos' command (but I don't know how to determine the reported block size), and I'd like to be able to calculate how much data was written for each backup based on the number of blocks dumped (I assume these blocks are the size I specify on the dump command line). In fact, how can I calculate how many blocks my tape can hold? (i.e. What is the biggest block number an 'mt rdhpos' or 'mt rdspos' will report for my tape?) Of course, an obvious solution to the last question is to write enough data to fill the tape and then check the output of 'mt rdhpos'. I'd rather not spend the hours needed and the unneeded wear on the tape to figure that out. Kevin