From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:35241 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751776AbbHNXtp (ORCPT ); Fri, 14 Aug 2015 19:49:45 -0400 Message-ID: <55CE7E94.7090102@oracle.com> Date: Sat, 15 Aug 2015 07:49:40 +0800 From: Anand Jain MIME-Version: 1.0 To: Timothy Normand Miller , Btrfs BTRFS Subject: Re: Can't mount degraded. How to remove/add drives OFFLINE? References: In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 08/15/2015 02:12 AM, Timothy Normand Miller wrote: > Sorry about that empty email. I hit a wrong key, and gmail decided to send. > > Anyhow, my replacement drive is going to arrive this evening, and I > need to know how to add it to my btrfs array. Here's the situation: > > - I had a drive fail, so I removed it and mounted degraded. that bit dangerous to do without the below patch. patch has more details why. > - I hooked up a replacement drive, did an "add" on that one, and did a > "delete missing". > - During the rebalance, the replacement drive failed, there were OOPSes, etc. > - Now, although all of my data is there, I can't mount degraded, > because btrfs is complaining that too many devices are missing (3 are > there, but it sees 2 missing). This is addressed in the patch [PATCH 23/23] Btrfs: allow -o rw,degraded for single group profile Thanks, Anand > So I could use some help with cleaning up this mess. All the data is > there, so I need to know how to either force it to mount degraded, or > add and remove devices offline. Where do I begin? > > Also, doesn't it seem a bit arbitrary that there are "too many > missing," when all of the data is there? If I understand correctly, > all four drives in my RAID1 should all have copies of the metadata, > and of the remaining three good drives, there should be one or two > copies of every data block. So it's all there, but btrfs has decided, > based on the NUMBER of missing devices, that it won't mount. > Shouldn't it refuse to mount if it knows there is data missing? For > that matter, why should it even refuse in that case? So some data > might missing, so it should throw some errors if you try to access > that missing data. Right? > > Thanks! >