From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f47.google.com ([74.125.83.47]:56971 "EHLO mail-ee0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751570AbaC3J6R (ORCPT ); Sun, 30 Mar 2014 05:58:17 -0400 Received: by mail-ee0-f47.google.com with SMTP id b15so5527176eek.6 for ; Sun, 30 Mar 2014 02:58:16 -0700 (PDT) Received: from linuxpc.localnet (188-22-82-140.adsl.highway.telekom.at. [188.22.82.140]) by mx.google.com with ESMTPSA id x45sm24667490eeu.23.2014.03.30.02.58.15 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 30 Mar 2014 02:58:15 -0700 (PDT) From: GEO <1g2e3o4@gmail.com> To: linux-btrfs@vger.kernel.org Subject: Backup: Compare sent snapshots Date: Sun, 30 Mar 2014 10:58:13 +0200 Message-ID: <8465933.4bvG1Xk5zJ@linuxpc> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi, I am doing backups regularly following the scheme of https://btrfs.wiki.kernel.org/index.php/Incremental_Backup It states we keep a local reference of the read only snapshot we sent to the backup drive, which I understand. But now I have a question: When I do a read only snapshot of home, send the difference to the backup drive, keep it until the next incremental step, send the difference to the backup drive, remove the old read only snapshot and so on... I wonder what happens if the read only snapshot I keep as a local reference got corrupted somehow. Then maybe too much difference would be sent which would not be dramatic, or too less, which would be. Is there a quick way I could compare the last sent snapshot to the local one, to make sure the local reference is still the same? Apart from that, imagine I somehow lost the local reference (e.g. delete it by mistake), would there still be a way to sync the difference to the last sent snapshot on the backup device?