From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tartarus.angband.pl ([89.206.35.136]:35209 "EHLO tartarus.angband.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965627AbcLVPO3 (ORCPT ); Thu, 22 Dec 2016 10:14:29 -0500 Received: from kilobyte by tartarus.angband.pl with local (Exim 4.88) (envelope-from ) id 1cK54b-00059K-7s for linux-btrfs@vger.kernel.org; Thu, 22 Dec 2016 16:14:25 +0100 Date: Thu, 22 Dec 2016 16:14:25 +0100 From: Adam Borowski To: linux-btrfs@vger.kernel.org Subject: Re: btrfs_log2phys: cannot lookup extent mapping Message-ID: <20161222151425.ecryyvnz2feaygrr@angband.pl> References: <89be6fee-5b18-7a9d-11ea-85abeab28022@ece.wisc.edu> <4e2fcf15-5af4-54b0-f7bb-46518b9bb5a4@ece.wisc.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Dec 22, 2016 at 10:11:35AM +0000, Duncan wrote: > Given the maturing-but-not-yet-fully-stable-and-mature state of btrfs > today, being no further from a usable current backup than the data you're > willing to lose, at least worst-case, remains an even stronger > recommendation than it is on fully mature and stable filesystem, kernel > and hardware. The usual rant about backups which I snipped is 110%[1] right, however I disagree that btrfs is worse than other filesystems for data safety. On one hand, btrfs: * is buggy * fails the KISS principle to a ridiculous degree * lacks logic people take for granted (especially on RAID) On the other, other filesystems: * suffer from silent data loss every time the disk doesn't notice an error! Allowing silent data loss fails the most basic requirement for a filesystem. Btrfs at least makes that loss noisy (single) so you can recover from backups, or handles it (redundant RAID). * don't have frequent snapshots to save you from human error (including other software) * make backups time-costly. rsync needs to at least stat everything, on a populated disk that's often half an hour or more, on btrfs a no-op backup takes O(1). So sorry, but I had enough woe with those "fully mature and stable" filesystems. Thus I use btrfs pretty much everywhere, backing up my crap every 24 hours, important bits every 3 hours. Meow! [1]. Above 100% as it's more true than people read it. -- Autotools hint: to do a zx-spectrum build on a pdp11 host, type: ./configure --host=zx-spectrum --build=pdp11