From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from magic.merlins.org ([209.81.13.136]:35551 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752397AbdIAUnb (ORCPT ); Fri, 1 Sep 2017 16:43:31 -0400 Date: Fri, 1 Sep 2017 13:43:29 -0700 From: Marc MERLIN To: Josef Bacik Cc: "linux-btrfs@vger.kernel.org" , Chris Murphy , Chris Mason , "bo.li.liu@oracle.com" , "fdmanana@suse.com" , David Sterba Subject: Re: BTRFS: error (device dm-2) in btrfs_run_delayed_refs:2960: errno=-17 Object already exists (since 3.4 / 2012) Message-ID: <20170901204329.GH30689@merlins.org> References: <20170715012216.njq6az3y34qyomtb@merlins.org> <20170715231245.GA28281@merlins.org> <20170829031637.GA15290@merlins.org> <20170829143955.GD15290@merlins.org> <20170830034001.rlwaqsitco65exqi@merlins.org> <20170831173607.GM15290@merlins.org> <5320FF2E-D183-4D2A-A155-49424E1CD60F@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <5320FF2E-D183-4D2A-A155-49424E1CD60F@fb.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Aug 31, 2017 at 05:48:23PM +0000, Josef Bacik wrote: > We are using 4.11 in production at fb with backports from recent (a month ago?) stuff. I’m relatively certain nothing bad will happen, and this branch has the most recent fsync() corruption fix (which exists in your kernel so it’s not new). That said if you are uncomfortable I can rebase this patch onto whatever base you want and push out a branch, it’s your choice. Keep in mind this is going to hold a lot of shit in memory, so I hope you have enough, and I’d definitely remove the sleep’s from your script, there’s no telling if this is a race condition or not and the overhead of the ref-verify stuff may cause it to be less likely to happen. Thanks, Thanks for the warning. I have 32GB of RAM in the server, and I probably use 8. Most of the rest is so that I can do btrfs check --repair without the machine dying :-/ I am concerned that I have a lot more metadata than I have memory: gargamel:~# btrfs fi df /mnt/btrfs_pool1 Data, single: total=10.66TiB, used=10.60TiB System, DUP: total=32.00MiB, used=1.20MiB Metadata, DUP: total=58.00GiB, used=12.76GiB GlobalReserve, single: total=512.00MiB, used=0.00B gargamel:~# btrfs fi df /mnt/btrfs_pool2 Data, single: total=5.07TiB, used=4.78TiB System, DUP: total=8.00MiB, used=640.00KiB Metadata, DUP: total=70.50GiB, used=66.58GiB GlobalReserve, single: total=512.00MiB, used=0.00B That's 13GB + 67GB. Is it going to fall over if I only have 32GB of RAM? If I stop mounting /mnt/btrfs_pool2 for a while, will 32GB of RAM cover the 13GB of metadata from /mnt/btrfs_pool1 ? Thanks, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/