From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ph.de-nserver.de ([85.158.179.214]:28710 "EHLO mail-ph.de-nserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751195AbbGMMye (ORCPT ); Mon, 13 Jul 2015 08:54:34 -0400 Message-ID: <55A3B508.7070500@profihost.ag> Date: Mon, 13 Jul 2015 14:54:32 +0200 From: Stefan Priebe - Profihost AG MIME-Version: 1.0 To: Austin S Hemmelgarn , "linux-btrfs@vger.kernel.org" Subject: Re: slowdown after one week References: <55A0BBD7.5000400@profihost.ag> <55A39F10.5040304@gmail.com> In-Reply-To: <55A39F10.5040304@gmail.com> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Am 13.07.2015 um 13:20 schrieb Austin S Hemmelgarn: > On 2015-07-11 02:46, Stefan Priebe wrote: >> Hi, >> >> while using a 40TB btrfs partition for VM backups. I see a massive >> slowdown after around one week. >> >> The backup task takes usally 2-3 hours. After one week it takes 20 >> hours. If i umount and remount the btrfs volume it takes 2-3 hours again. >> >> Kernel 4.1.1 >> > I've been seeing similar (although much less drastic) slowdowns over > time myself pretty much since I started using BTRFS (IIRC, sometime > around 3.16). If you're not constantly writing to that backup volume, > you might want to consider setting up automounting for it. > Yes but that's awful. it's a bug. It would be very nice if someone involved in the btrfs development can comment on that one.