From owner-freebsd-questions@FreeBSD.ORG Thu May 24 03:20:07 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 320E616A421 for ; Thu, 24 May 2007 03:20:07 +0000 (UTC) (envelope-from on@cs.ait.ac.th) Received: from mail.cs.ait.ac.th (mail.cs.ait.ac.th [192.41.170.16]) by mx1.freebsd.org (Postfix) with ESMTP id ACA0113C447 for ; Thu, 24 May 2007 03:20:06 +0000 (UTC) (envelope-from on@cs.ait.ac.th) Received: from banyan.cs.ait.ac.th (banyan.cs.ait.ac.th [192.41.170.5]) by mail.cs.ait.ac.th (8.13.1/8.12.11) with ESMTP id l4O3JxD4018509 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 24 May 2007 10:19:59 +0700 (ICT) Received: (from on@localhost) by banyan.cs.ait.ac.th (8.13.3/8.12.11) id l4O3Jw50035876; Thu, 24 May 2007 10:19:58 +0700 (ICT) Date: Thu, 24 May 2007 10:19:58 +0700 (ICT) Message-Id: <200705240319.l4O3Jw50035876@banyan.cs.ait.ac.th> From: Olivier Nicole To: jason+lists.freebsd-questions@lixfeld.ca In-reply-to: <28E0DBBA-BB24-4D6B-AE65-07EB5254025C@lixfeld.ca> (message from Jason Lixfeld on Wed, 23 May 2007 19:27:05 -0400) References: <28E0DBBA-BB24-4D6B-AE65-07EB5254025C@lixfeld.ca> X-Virus-Scanned: on CSIM by amavisd-milter (http://www.amavis.org/) Cc: freebsd-questions@freebsd.org Subject: Re: Backup advice X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 May 2007 03:20:07 -0000 Hi, > So I feel a need to start backing up my servers. To that end, I've > decided that it's easier for me to grab an external USB drive instead > of a tape. It's certainly faster, easier and cheaper now days. > It would seem dump/restore are the tools of choice. This really repends of what you are backuping. Dump is OS specific. Ifwhat really, really matters is the data, notthe OS, not the software, tar may be more generic and could even be recovered on a Windows machine. > My > backup strategy is pretty much "I don't want to be screwed if my RAID > goes away". That said I have a few questions along those lines: > - Most articles I've read suggest a full backup, followed by > incremental backups. Is there any real reason to adopt that format > for a backup strategy like mine, or is it reasonable to just do a > dump 0 nightly? I think the only reason to do just one full backup > per 'cycle' would be to preserve system resources, as I'm sure it's > fairly taxing on the system during dump 0 times. Depends on your retore needs. Once you have backup you may soon find out that you want to restore data from 2 days ago, if you keep only the latest dump 0, you cannot. If you plan to keep several runs of dump 0, going incremental will save you time and disk space (at the cost of some time in case of recovery, but we expect recovery will never be needed...) > - Can dump incrementally update an existing dump, or is the idea that > a dump is a closed file and nothing except restore should ever touch it? No. Incremental dumps are just other files, so for 50 GB of data and 5 GB changing each day, you would need a backup space equal to 50GB for dump 0 plus 5GB for each incremental. > - How much does running a backup through gzip actually save? Is > taxing the system to compress the dump and the extra time it takes > actually worth it, assuming I have enough space on my backup drive to > support a dump 0 or two? Not sure if dump is not already compressed. > - Other folks dumping to a hard drive at night? Care to share any of > your experiences/rationale? I have been running Amanda for years, on tape because the tape drive is still solid, next support will be external drive (USB, eSATA, whatever comes next). I backup FreeBSD, some Linuxes, various windows... I use Gnu tar with Amanda, so my tapes can be read on many OS'es. Olivier