From owner-freebsd-questions Thu Nov 14 20:25:29 2002 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 AF92237B401 for ; Thu, 14 Nov 2002 20:25:27 -0800 (PST) Received: from mail4.sea.registeredsite.com (mail4.sea.registeredsite.com [66.111.73.204]) by mx1.FreeBSD.org (Postfix) with ESMTP id A218743E77 for ; Thu, 14 Nov 2002 20:25:23 -0800 (PST) (envelope-from admin@asarian-host.net) Received: from asarian-host.net (asarian-host.net [216.122.74.112]) by mail4.sea.registeredsite.com (8.12.5/8.12.5) with ESMTP id gAF4PKIH032030 for ; Thu, 14 Nov 2002 23:25:22 -0500 Comments: To protect the identity of the sender, certain header fields are either not shown, or masked. Anonymous email addresses for asarians can be requested by filling in the appropriate form at: https://asarian-host.net/cgi-bin/signup.cgi Received: (from root@localhost) by asarian-host.net (8.11.0/8.11.0) id gAF4PKC21333 for freebsd-questions@freebsd.org; Fri, 15 Nov 2002 05:25:20 +0100 (CET) (envelope-from admin@asarian-host.net) Posted-Date: Fri, 15 Nov 2002 05:25:20 +0100 (CET) From: Mark Message-Id: <200211150425.GAF4PFI21317@asarian-host.net> Date: Fri, 15 Nov 2002 05:25:10 +0100 X-Authenticated-Sender: admin@asarian-host.net Subject: Re: restore question X-Trace: zF4YE2bo5smAkNXQgBBViUolZ/sT4AxpNETYJ6Qs+q/xtJO+/ZZu4ygGcmsLKdeX X-Complaints-To: abuse@asarian-host.net X-Abuse-Info: Please be sure to forward a copy of ALL headers X-Abuse-Info: Otherwise we are unable to process your complaint Organization: Asarian-host To: References: <020901c28b6f$f0b241c0$1200a8c0@gsicomp.on.ca> <127.0.0.1.20021114195745.01099888@mail.sage-one.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Auth: Asarian-host PGP signature iQEVAwUAPdR3LjFqW1BleBN9AQFxNAf9EY8ww+gwM0oDbO8o3AlVSCfcY6qsy37h LkW/iZZpdBFnFhh69VcYp4iuxe4HUWpeakv4uOffAeJZ7nhH8SoPjoZqyZAhQsnX 7U+QD8FF7DSJH/4VkZrIFNN2nevqXgcGzaeq2zgWXdCL2jfYmCgeM4boLnAIT3p9 KvaamdeJwqiEWl8HD9VLOoC+SvOl/y9qiOYwqETwjOs8sAlklgE2a0eLykApHuyA 42/n5qcFjp8Z+KTxinXt0a0V6HdhBUqxp2U7q3iu3OehtFs+nzbbhCs85wQoxlW9 mXFdxUzXA3C26AmxKqK7Rpz/DmNT3Pk7K4d+4qeq7pImTGLMpWk0GQ== =kmN5 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG ----- Original Message ----- From: "Jack L. Stone" To: "Mark" ; "Matthew Emmerton" ; "R. Zoontjens" ; Sent: Friday, November 15, 2002 2:57 AM Subject: Re: restore question > There IS a program similar to Ghost with respect to making an image. > It's called "dd" and it's already installed on your FBSD system. > Run "man 1 dd" for options. > > Bear in mind that if you want an image of your whole disk, you'll need > the 2nd one to be at least equal in size, but you will lose any part of the > 2nd HD that is larger than HD #1 (I think Ghost does that too > -- or used to). dd can be limited to imaging only a slice however..... > > This questions comes up monthly and the archives has numerous postings > over the past several months that will fill more details..... Yes, the question comes up many times; yet the right answer keeps lacking. :) Before I asked, I had, of course, done a bit of searching. And found that there are many disadvantages to using "dd". For one, using disk-blocks, instead of reading files sequentially, like tar and Ghost do, enhances the risk of data-corruption. For two, with "dd" you need to unmount filesystems first. Which makes it pretty useless on a production server. Yeah, like I can really afford to have my /usr slice be absent for half-an-hour. I think not. :) Actually, we are talking about backup, but the real issue is restore. Everybody can make a tar of the root system, or a dd image. Sure. Restoring it, however, in a manner that will yield you a bootable, instant runnable system, now that is another matter. And what to do with special cases like /dev? In all my perusing the net, I have yet to encounter one solution that said: "This is how you can make a full system backup, with this image, that you can immediately restore on a blank harddisk, and have your system up and running again." Many suggestions I read about ways to backup. But, like I said, restoring is the real issue. I can backup /proc for sure; the wisdom of restoring it on a life system, however, is another matter. That is why the only clean way of doing this, would be to make a disk-image, like Ghost does. And Ghost, so unlike dd, does NOT use disk-blocks, but reads files sequentially. When making a disk image, Ghost basically just does several partition images, and then adds partition table info to the overall disk image. No need to "zero" out the disk first, like with dd, so as not to have it waste too much space. Still looking... - Mark To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message