From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from rin.romanrm.net ([91.121.86.59]:42660 "EHLO rin.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751901AbeF2Heh (ORCPT ); Fri, 29 Jun 2018 03:34:37 -0400 Date: Fri, 29 Jun 2018 12:34:34 +0500 From: Roman Mamedov To: Marc MERLIN Cc: linux-btrfs@vger.kernel.org Subject: Re: So, does btrfs check lowmem take days? weeks? Message-ID: <20180629123434.551e3841@natsu> In-Reply-To: <20180629072210.nxvtwbokblol7xcb@merlins.org> References: <20180629042707.vrjwbytg6bxmrgjg@merlins.org> <6658a593-3b4a-f1ef-f550-2fb951b2517d@gmx.com> <20180629052825.tifg2aw7oy3qyyvw@merlins.org> <3b240898-a96d-77f6-efb9-f0af81ee0cd1@gmx.com> <20180629060657.qrtcxfcy22zkstfw@merlins.org> <20180629065903.xgwpvaa2vuiys75r@merlins.org> <20180629120954.4bbcd174@natsu> <20180629072210.nxvtwbokblol7xcb@merlins.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, 29 Jun 2018 00:22:10 -0700 Marc MERLIN wrote: > On Fri, Jun 29, 2018 at 12:09:54PM +0500, Roman Mamedov wrote: > > On Thu, 28 Jun 2018 23:59:03 -0700 > > Marc MERLIN wrote: > > > > > I don't waste a week recreating the many btrfs send/receive relationships. > > > > Consider not using send/receive, and switching to regular rsync instead. > > Send/receive is very limiting and cumbersome, including because of what you > > described. And it doesn't gain you much over an incremental rsync. As for > > Err, sorry but I cannot agree with you here, at all :) > > btrfs send/receive is pretty much the only reason I use btrfs. > rsync takes hours on big filesystems scanning every single inode on both > sides and then seeing what changed, and only then sends the differences I use it for backing up root filesystems of about 20 hosts, and for syncing large multi-terabyte media collections -- it's fast enough in both. Admittedly neither of those case has millions of subdirs or files where scanning may take a long time. And in the former case it's also all from and to SSDs. Maybe your use case is different where it doesn't work as well. But perhaps then general day-to-day performance is not great either, so I'd suggest looking into SSD-based LVM caching, it really works wonders with Btrfs. -- With respect, Roman