From owner-freebsd-isp@FreeBSD.ORG Mon Mar 29 13:12:07 2004 Return-Path: Delivered-To: freebsd-isp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CC53C16A4CF for ; Mon, 29 Mar 2004 13:12:07 -0800 (PST) Received: from enterprise.ecore.net (enterprise.ecore.net [212.223.99.1]) by mx1.FreeBSD.org (Postfix) with SMTP id B726943D2F for ; Mon, 29 Mar 2004 13:12:06 -0800 (PST) (envelope-from cs@cheasy.de) Received: (qmail 18936 invoked from network); 29 Mar 2004 21:12:01 -0000 Received: from p50840181.dip0.t-ipconnect.de (HELO www.cheasy.de) (80.132.1.129) by cheasy.de with SMTP; 29 Mar 2004 21:12:01 -0000 From: Christoph Sold To: freebsd-isp@freebsd.org, sellis@telus.net Date: Mon, 29 Mar 2004 22:11:51 +0200 User-Agent: KMail/1.6.1 References: <20040329183323.GC51870@telus.net> In-Reply-To: <20040329183323.GC51870@telus.net> MIME-Version: 1.0 Content-Disposition: inline Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message-Id: <200403292211.58942.cs@cheasy.de> Subject: Re: tape backup from remote X-BeenThere: freebsd-isp@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Internet Services Providers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Mar 2004 21:12:07 -0000 =2D----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Monday 29 March 2004 20:33, Sean Ellis wrote: > Hello, G'day, > I have a very general question about backing up to tape from a remote > computer. The tape drive is unfamiliar territory for me, and I'm > looking for recommendations for a sequence of steps to take. Wise decision. > Both machines are running fbsd 4.*, the local machine is a recent 4.9 > STABLE, and the tape drive is a Conner CTD800R-S. Will it be > possible, or advisable, to use a utility to back up over the net > directly to the tape, or should we be creating a local mirror and > backing up this? Backing up remotely can yield _very_ unsatisfying results for several=20 reasons: =2D - If there is not enough bandwith, the tape "trashes": After backing up= =20 a few blocks, the tape has to stop, rewind, then re-synchronize and=20 append to the previously written data. This is _much_ slower than=20 nominal backup speed. =2D - If the network latency is too high, the backup software may get=20 confused and abort. =2D - If the connection is dropped during backup, may tools invalidate the= =20 whole backup. There are both commercial as well as open source tools dealing with this=20 situation. I used amanda (in the ports) to backup multiple remote=20 clients to one backup machine. Never experienced any data loss during=20 restore. > I know that these are very basic questions, but I felt that posting > here in isp might give me a more informed response.=20 Have a look at http://www.thestoragegroup.com/pubs.html , the links=20 there show many aspects of backup and recovery. Another hint, though: DDS (DAT) is not up to the job. I personally=20 ditched all DDS devices after multiple data loss events being caused by=20 worn tapes, never properly written tapes, over-aged tapes. Never=20 happend with DLT, though. HTH =2D -Christoph Sold =2D----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFAaIMHjGVuYEZ1RPYRAuy+AJ473q/Q5JXWodJu3aeO1y3pQVFT7wCfUkAr kOiW2k50MoiflSIxUO46+KE=3D =3DtPFi =2D----END PGP SIGNATURE-----