From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f53.google.com ([209.85.215.53]:38333 "EHLO mail-lf0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752023AbdHLWlX (ORCPT ); Sat, 12 Aug 2017 18:41:23 -0400 Received: by mail-lf0-f53.google.com with SMTP id y15so27766123lfd.5 for ; Sat, 12 Aug 2017 15:41:22 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <21234.192.168.42.222.1502253143.squirrel@mail> <22169.183.88.87.49.1502260598.squirrel@mail> <27218.183.88.87.49.1502426431.squirrel@mail> <13031.192.168.42.222.1502431206.squirrel@mail> <1243.49.228.123.163.1502505534.squirrel@mail> <1420.49.228.123.163.1502514511.squirrel@mail> From: "Janos Toth F." Date: Sun, 13 Aug 2017 00:41:06 +0200 Message-ID: Subject: Re: btrfs issue with mariadb incremental backup To: Chris Murphy Cc: siranee.ja@tpc.co.th, Btrfs BTRFS , voravat@tpcorp.co.th Content-Type: text/plain; charset="UTF-8" Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Sat, Aug 12, 2017 at 11:34 PM, Chris Murphy wrote: > On Fri, Aug 11, 2017 at 11:08 PM, wrote: > > I think the problem is that the script does things so fast that the > snapshot is not always consistent on disk before btrfs send starts. > It's just a guess though. If I'm right, this means the rsync mismaches > mean the destination snapshots are bad. Hmm. I was wondering about this exact issue the other day when I fiddled with my own backup script. - Should I issue a sync between creating a snapshot and starting to rsync (or send/receive) the content of that fresh snapshot to an external backup storage? I dismissed the thought because I figured rsync should see the proper state regardless if some data is still waiting in the system write-back cache. Now I am confused again. Is it only for send/receive? (I don't use that feature yet but thought about switching to it from rsync.)