From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from static.68.134.40.188.clients.your-server.de ([188.40.134.68]:54203 "EHLO mail02.iobjects.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932435AbbJ0PCC (ORCPT ); Tue, 27 Oct 2015 11:02:02 -0400 Subject: Re: Bad fs performance, IO freezes To: "cheater00 ." References: <562E37F4.9080602@oracle.com> <562F638B.1040701@gmail.com> <562F7C7B.6060408@gmail.com> Cc: Btrfs BTRFS From: =?UTF-8?Q?Holger_Hoffst=c3=a4tte?= Message-ID: <562F91E7.5030407@googlemail.com> Date: Tue, 27 Oct 2015 16:01:59 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 10/27/15 15:43, cheater00 . wrote: > I have remounted without autodefrag and the issue keeps on happening. At the risk of stating the obvious, the simplest thing is to stop using COW with compression for torrents. It's fundamentally not useful to have many small in-place writes, irregular compression and not encounter insane levels of fragmentation, which - at least in the current state of btrfs - is known to cause long stalls. Some fixes for that will be in 4.4. Until then just do yourself a favor, stop doing the wrong thing and put torrent downloads into a directory where they won't get COWed. See the wiki at: https://btrfs.wiki.kernel.org/index.php/FAQ#Can_copy-on-write_be_turned_off_for_data_blocks.3F for more. -h