From owner-freebsd-hackers Sun Oct 29 23:36:55 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from ren.sasknow.com (ren.sasknow.com [207.195.92.131]) by hub.freebsd.org (Postfix) with ESMTP id F06C837B479 for ; Sun, 29 Oct 2000 23:36:52 -0800 (PST) Received: from localhost (ryan@localhost) by ren.sasknow.com (8.9.3/8.9.3) with ESMTP id BAA07586; Mon, 30 Oct 2000 01:40:30 -0600 (CST) (envelope-from ryan@sasknow.com) Date: Mon, 30 Oct 2000 01:40:30 -0600 (CST) From: Ryan Thompson To: Leif Neland Cc: Matt Dillon , freebsd-hackers@FreeBSD.ORG Subject: Re: Filesystem holes In-Reply-To: <01a801c04236$ed0a0d20$0e00a8c0@neland.dk> Message-ID: Organization: SaskNow Technologies [www.sasknow.com] MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Leif Neland wrote to Ryan Thompson and Matt Dillon: > > What will happen, if somebody (possibly you, as mahordomo says), tries to > make a backup of that file. Make sure to use a program that can cope ;-) > Will the copy also be with holes, or would that file suddenly use all 96GB? > It will at least do so, if one does cat file>file.bak > Probably tar will do the same. Actually, tar will handle holes elegantly (this I have tested), with the --sparse option. Older versions would not. cat and other similar "filters" are naive, as they simply block I/O. Backing up with tar and/or a filesystem dump would be just as effective as with any other storage strategy. cat file > file.bak on even a 2GB file is probably not something that would be popular, anyway. > I'd be afraid to create something which could easily blow up by having > normal operations applied to it. That's a valid concern. That's the biggest drawback I see to the overall strategy... But, specialized problems sometimes encourage specialized solutions. > > Leif > -- Ryan Thompson Network Administrator, Accounts Phone: +1 (306) 664-1161 SaskNow Technologies http://www.sasknow.com #106-380 3120 8th St E Saskatoon, SK S7H 0W2 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message