From: Greg Freemyer Subject: Re: Shorten the backup process? Date: Sat, 9 Oct 2010 16:56:08 -0400 Message-ID: References: <4CB0D214.1070301@cybericom.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-ext4@vger.kernel.org To: Chris Lee Return-path: Received: from mail-iw0-f174.google.com ([209.85.214.174]:53374 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757112Ab0JIU4a convert rfc822-to-8bit (ORCPT ); Sat, 9 Oct 2010 16:56:30 -0400 Received: by iwn6 with SMTP id 6so1738914iwn.19 for ; Sat, 09 Oct 2010 13:56:30 -0700 (PDT) In-Reply-To: <4CB0D214.1070301@cybericom.co.uk> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sat, Oct 9, 2010 at 4:35 PM, Chris Lee = wrote: > > Hi All, > I hope this to bee food for thought as I am not able to code such a t= hing nor am I in need of such a thing but it seemed like a good idea wh= en it struck me, so; > When an filesystem is snap shotted it is a function of the =A0running= filesystem to provide the data in that snapshot. (or is that lvms doin= g?) > Most users who use snapshots for backup are going to mount the snap s= hot and then tar it up. > Would it be a good idea to provide a virtual file through something l= ike the sysfs that is a tar representation of the snapshot so that a ba= ckup can just copy the tar file off as needed? > > Thanks for reading, > > Regards, > Chris. That seems like an overly specialized feature for the kernel. And even if it were a good idea conceptually: 1) ext4 does not currently offer filesystem snapshot capability. It is handled at a lower level in the block stack. (ie. either in the hardware array or via device mapper). 2) Those lower levels simply are aware of blocks / sectors, not files. Thus they have no ability to create a "tar" file. fyi: btrfs is a more integrated filesystem, so it is at least technically feasible with it. Greg -- Greg Freemyer Head of EDD Tape Extraction and Processing team Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer CNN/TruTV Aired Forensic Imaging Demo - =A0=A0 http://insession.blogs.cnn.com/2010/03/23/how-computer-evidence-= gets-retrieved/ The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html