From owner-freebsd-questions@FreeBSD.ORG Wed Mar 16 13:50:49 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 46CBC16A4CE for ; Wed, 16 Mar 2005 13:50:49 +0000 (GMT) Received: from mailgw.dgrp.sk (mailgw.dgrp.sk [195.28.127.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id 344A643D2F for ; Wed, 16 Mar 2005 13:50:48 +0000 (GMT) (envelope-from lk@tempest.sk) Received: by mailgw.dgrp.sk (Postfix, from userid 1003) id 0F80934A5A8; Wed, 16 Mar 2005 14:50:47 +0100 (CET) Received: from webmail.tempest.sk (unknown [195.28.100.38]) by mailgw.dgrp.sk (Postfix) with ESMTP id 8E77A34A5A2; Wed, 16 Mar 2005 14:50:43 +0100 (CET) Received: from lk.tempest.sk ([195.28.109.47]) by webmail.tempest.sk (Lotus Domino Release 6.5.2) with ESMTP id 2005031614504322-551 ; Wed, 16 Mar 2005 14:50:43 +0100 Received: from lk.tempest.sk (localhost [127.0.0.1]) by lk.tempest.sk (8.13.1/8.12.9) with ESMTP id j2GDo2ni014893; Wed, 16 Mar 2005 14:50:02 +0100 (CET) (envelope-from koren@lk.tempest.sk) Received: (from koren@localhost) by lk.tempest.sk (8.13.1/8.13.1/Submit) id j2GDo2fR014888; Wed, 16 Mar 2005 14:50:02 +0100 (CET) (envelope-from koren) Date: Wed, 16 Mar 2005 14:50:02 +0100 (CET) Message-Id: <200503161350.j2GDo2fR014888@lk.tempest.sk> From: Ludo Koren To: xfb52@dial.pipex.com In-reply-to: <42381DF3.5060906@dial.pipex.com> (message from Alex Zbyslaw on Wed, 16 Mar 2005 11:52:19 +0000) References: <200503140938.j2E9c2EM024428@lk.tempest.sk> <42370004.5060506@dial.pipex.com> <200503160953.j2G9rjKR003358@lk.tempest.sk> <42381DF3.5060906@dial.pipex.com> X-MIMETrack: Itemize by SMTP Server on Domino1/DGRP(Release 6.5.2|June 01, 2004) at 16.03.2005 14:50:43, Serialize by Router on Domino1/DGRP(Release 6.5.2|June 01, 2004) at 16.03.2005 14:50:43, Serialize complete at 16.03.2005 14:50:43 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on mailgw X-Spam-Level: X-Spam-Status: No, score=-2.5 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.0.2 cc: freebsd-questions@freebsd.org Subject: Re: Backup on DDS-4 tapes 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, 16 Mar 2005 13:50:49 -0000 > Ludo Koren wrote: >> It doesn't help either... The result is the same. >> >> > Just to check I'm understanding your problem correctly -- > you're expecting to write much more data to the tape than is > actually being written. That's right. I suppose that 54GB of data could fit on 2 40GB tapes... > If that's correct, then there's a couple things I can think of: > 1) Your tape drive isn't doing hardware compression. Check the > manual and see if there are any dip switches you need to set. > (Make a note of how they're set before you change anything, so > you can go back to what you had originally!). I'll check this > When you say the result is the same, if it used exactly the > same number of tapes (down to the decimal point) then that > definitely suggests that your tape drive is not compressing. > 2) The data you're writing to the tape is already mostly > compressed, so you won't fit as much as you might if it were > uncompressed data. I will do statistics about files. > Also, the 40Gb per tape that you quote is, I think, the MAXIMUM > amount of data the tape will take. It's only 20Gb native. > 40Gb is how much will fit at optimum compression, which you > never get. > It's unlikely to be a FreeBSD problem because I regularly fit > 6-7Gb on a DDS-2, which has a native size of 4Gb. I use dump > options like the ones in my last message. > --Alex Thank, for your suggestions. lk