From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:51476 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750833AbbL1BWB (ORCPT ); Sun, 27 Dec 2015 20:22:01 -0500 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1aDMVb-00046q-Di for linux-btrfs@vger.kernel.org; Mon, 28 Dec 2015 02:21:59 +0100 Received: from ip98-167-165-199.ph.ph.cox.net ([98.167.165.199]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 28 Dec 2015 02:21:59 +0100 Received: from 1i5t5.duncan by ip98-167-165-199.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 28 Dec 2015 02:21:59 +0100 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: Btrfs scrub failure for raid 6 kernel 4.3 Date: Mon, 28 Dec 2015 01:21:54 +0000 (UTC) Message-ID: References: <567FEEB6.3080701@online.no> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Waxhead posted on Sun, 27 Dec 2015 14:59:18 +0100 as excerpted: > I have a "toy-array" of 6x USB drives hooked up to a hub where I made a > btrfs raid 6 data+metadata filesystem. Just noting as an aside comment to the main thread... While doing this with a "toy-array" for experimental purposes is fine and indeed encouraged, do your research and LOTS of testing before trying to setup particularly multi-device btrfs over USB for normal use. There have been a number of trouble reports posted for USB connected devices, where the trouble simply vanished when the devices were attached via (e)SATA. Apparently various SATA/USB bridge controllers aren't entirely reliable, a few USB root hubs likewise (tho the bridge-controllers are the most common culprit), and USB itself wasn't really designed for this sort of thing, tho obviously many people use it for attaching storage today. Personally, while I might use btrfs on single-device USB attached storage, I'd be extremely hesitant to do multi-device btrfs via USB, and would definitely test it (VERY!) well before considering it usable if I did, as there's just too many ways multiple USB-attached devices can get out of sync with each other, breaking the filesystem. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman