From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw0-f179.google.com ([209.85.161.179]:36310 "EHLO mail-yw0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752137AbcDSDGI (ORCPT ); Mon, 18 Apr 2016 23:06:08 -0400 Received: by mail-yw0-f179.google.com with SMTP id o66so3901590ywc.3 for ; Mon, 18 Apr 2016 20:06:08 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: Date: Tue, 19 Apr 2016 11:06:07 +0800 Message-ID: Subject: Re: Install to or Recover RAID Array Subvolume Root? From: David Alcorn To: Btrfs BTRFS Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Nicolas: My flash drive uses BTRFS and I am comfortable with your instructions with one exception. What does "update /etc/default/grub" mean? Currently, I am waiting for a scrub to verify that all is in good order before fixing the problem. On 4/19/16, Nicholas D Steeves wrote: > On 18 April 2016 at 01:22, David Alcorn wrote: >> The goal is to install to a subvolume on the array >> without disturbing date on other array subvolumes. >> >> I erred and shutdown my NAS during a balance. Grub lost track of my >> root. Root was on RAID 6 array subvolid 257. I can boot a different >> root from a USB flash drive but neither update-grub not install-grub >> sees my old root on array subvolid 257. I am happy to either recover >> or lose array subvolid 257 but do not want to lose data on other array >> subvol's. I prefer to have my root on the array rather than a flash >> drive. The balance completed successfully after I booted from the >> flash drive. > > Is your flash drive formatted btrfs? If it is, you could always > snapshot it, send the snapshot to your array, set property of that > subvolume to RW, chroot, update fstab to mount / with the appropriate > subvol=option, update /etc/default/grub, reinstall grub and > update-grub, and reboot with your / as a subvolume on your array. I'm > in the process of documenting how to do this on the Debian wiki. > Please let me know if I should put a rush on it. It uses the subvol= > option rather than changing the volume's default subvol. > > Cheers, > Nicholas >