From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from atl4mhob16.myregisteredsite.com ([209.17.115.54]:57622 "EHLO atl4mhob16.myregisteredsite.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752551AbaCNNph (ORCPT ); Fri, 14 Mar 2014 09:45:37 -0400 Received: from mailpod1.hostingplatform.com ([10.30.71.114]) by atl4mhob16.myregisteredsite.com (8.14.4/8.14.4) with ESMTP id s2EDjavA027608 for ; Fri, 14 Mar 2014 09:45:36 -0400 Message-ID: <5323082B.50600@chinilu.com> Date: Fri, 14 Mar 2014 06:46:19 -0700 From: George Mitchell Reply-To: george@chinilu.com MIME-Version: 1.0 To: Duncan <1i5t5.duncan@cox.net>, linux-btrfs@vger.kernel.org Subject: Re: Incremental backup for a raid1 References: <1564384.fRV1HUkfCq@fuchsia> <1549230.7yEi5AM4H9@fuchsia> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Actually, an interesting concept would be to have the initial two drive RAID 1 mirrored by 2 additional drives in 4-way configuration on a second machine at a remote location on a private high speed network with both machines up 24/7. In that case, if such a configuration would work, either machine could be obliterated and the data would survive fully intact in full duplex mode. It would just need to be remounted from the backup system and away it goes. Just thinking of interesting possibilities with n-way mirroring. Oh how I would love to have n-way mirroring to play with! On 03/14/2014 04:24 AM, Duncan wrote: > Michael Schuerig posted on Fri, 14 Mar 2014 09:56:20 +0100 as excerpted: > > [Duncan posted...] > >>> 3) Disconnect the backup device(s). (Don't btrfs device delete, this >>> would remove the copy. Just disconnect.) > Hmm... Looking back at what I wrote... > > Presumably either have the filesystem unmounted for the disconnect (and > ideally, the system off, tho with modern drives in theory that's not an > issue, but still good if it can be done), or at least remounted read-only. > > I had guessed that was implicit, but making it explicit is probably best > all around, just in case. At least I can rest better with it, having > made that explicit. >