From owner-freebsd-questions@FreeBSD.ORG Tue Jan 18 12:57:08 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 0144016A4CE for ; Tue, 18 Jan 2005 12:57:08 +0000 (GMT) Received: from male.aldigital.co.uk (male.thebunker.net [213.129.64.13]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4518F43D39 for ; Tue, 18 Jan 2005 12:57:07 +0000 (GMT) (envelope-from matthew@thebunker.net) Received: from gravitas.thebunker.net (gateway.ash.thebunker.net [213.129.64.4]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (No client certificate requested) by male.aldigital.co.uk (Postfix) with ESMTP id 83EFC9777E; Tue, 18 Jan 2005 12:57:05 +0000 (GMT) Received: from gravitas.thebunker.net (localhost [127.0.0.1]) j0ICv1LU074211; Tue, 18 Jan 2005 12:57:01 GMT (envelope-from matthew@gravitas.thebunker.net) Received: (from matthew@localhost) by gravitas.thebunker.net (8.13.1/8.13.1/Submit) id j0ICv06w074210; Tue, 18 Jan 2005 12:57:00 GMT (envelope-from matthew) Date: Tue, 18 Jan 2005 12:57:00 +0000 From: Matthew Seaman To: Anthony Atkielski Message-ID: <20050118125700.GA72972@gravitas.thebunker.net> Mail-Followup-To: Matthew Seaman , Anthony Atkielski , freebsd-questions@freebsd.org References: <20050114145740.A11218@starfire.mn.org> <1537802471.20050114224944@wanadoo.fr> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="BXVAT5kNtrzKuDFl" Content-Disposition: inline In-Reply-To: <1537802471.20050114224944@wanadoo.fr> User-Agent: Mutt/1.5.6i cc: freebsd-questions@freebsd.org Subject: Re: Backups / Dump etc 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: Tue, 18 Jan 2005 12:57:08 -0000 --BXVAT5kNtrzKuDFl Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jan 14, 2005 at 10:49:44PM +0100, Anthony Atkielski wrote: > John writes: >=20 > J> If you are running FreeBSD 5.x, you get the cool "L" option on > J> dump which will automatically snapshot the mounted filesystems. >=20 > What exactly is meant by a "snapshot," and how much extra disk space > does it require when dump runs? I've seen the warnings when I run dump > on a running multiuser system in 5.x, and I turned on the L option, > since I'm not hurting on disk space, but I do wonder how much space it > requires (I can't imagine a snapshot that doesn't require a lot of disk > space). Actually the snapshot requires practically no additional space: it's a view of the filesystem at a particular point in time. Any subsequent modifications -- new or edited or deleted files, etc. are held in memory: they do take up a bit more space, but only until dump(8) finishes running and all of the recent filesystem traffic can be merged. Cheers, Matthew --=20 Dr Matthew J Seaman MA, D.Phil. 8 Dane Court Manor School Rd PGP: http://www.infracaninophile.co.uk/pgpkey Tilmanstone Tel: +44 1304 617253 Kent, CT14 0JL UK --BXVAT5kNtrzKuDFl Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (FreeBSD) iQCVAwUBQe0HnJr7OpndfbmCAQIXtwQA2ug6co4ATkcRXXj+1zI/kpE17/XFTnuN 28jEyBdSWUWU3zW6z+mfe9Z4GsYyV12lhBo1mREDtJowNxMZbmNIgECeR3ZVDHqV 6T26zFCyVqMsIr9pxLgzqEyE/SxpuP0NntWpiGgiBr6XY3YVZ13f63OcZz2qDdo4 iW982Y1GLC8= =jd7G -----END PGP SIGNATURE----- --BXVAT5kNtrzKuDFl--