From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f50.google.com ([74.125.83.50]:47203 "EHLO mail-ee0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753431AbaACXER (ORCPT ); Fri, 3 Jan 2014 18:04:17 -0500 Received: by mail-ee0-f50.google.com with SMTP id c41so6873781eek.37 for ; Fri, 03 Jan 2014 15:04:15 -0800 (PST) Message-ID: <52C741F5.7030106@gmail.com> Date: Sat, 04 Jan 2014 00:04:21 +0100 From: =?ISO-8859-1?Q?Joshua_Sch=FCler?= MIME-Version: 1.0 To: Jim Salter CC: linux-btrfs@vger.kernel.org Subject: Re: btrfs raid1 and btrfs raid10 arrays NOT REDUNDANT References: <52C73987.7000106@jrs-s.net> <52C73D1A.8060805@gmail.com> <52C7402A.7050605@jrs-s.net> In-Reply-To: <52C7402A.7050605@jrs-s.net> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Am 03.01.2014 23:56, schrieb Jim Salter: > I actually read the wiki pretty obsessively before blasting the list - > could not successfully find anything answering the question, by scanning > the FAQ or by Googling. > > You're right - mount -t btrfs -o degraded /dev/vdb /test worked fine. don't forget to btrfs device delete missing See https://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices > > HOWEVER - this won't allow a root filesystem to mount. How do you deal > with this if you'd set up a btrfs-raid1 or btrfs-raid10 as your root > filesystem? Few things are scarier than seeing the "cannot find init" > message in GRUB and being faced with a BusyBox prompt... which is > actually how I initially got my scare; I was trying to do a walkthrough > for setting up a raid1 / for an article in a major online magazine and > it wouldn't boot at all after removing a device; I backed off and tested > with a non root filesystem before hitting the list. Add -o degraded to the boot-options in GRUB. If your filesystem is more heavily corrupted then you either need the btrfs tools in your initrd or a rescue cd > > I did find the -o degraded argument in the wiki now that you mentioned > it - but it's not prominent enough if you ask me. =) > > [snip] Joshua