From mboxrd@z Thu Jan 1 00:00:00 1970 From: Carl Cook Subject: Re: Adding a disk fails Date: Thu, 20 Jan 2011 15:10:54 -0800 Message-ID: <201101201510.54418.CACook@quantum-sci.com> References: <201101201318.40686.CACook@quantum-sci.com> <4D38B382.1050709@libero.it> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" To: linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <4D38B382.1050709@libero.it> List-ID: On Thu 20 January 2011 14:13:22 Goffredo Baroncelli wrote: > To add another disk you don't have to run mkfs.btrfs. For example: > > # add the first disk > mkfs.btrfs /dev/sdb > # mount the disk > mount /dev/sdb /media/backups > > # add another disk to the first one > btrfs device add /dev/sdc /media/backup Thanks Goffredo but as I say, I did this and it responds with "ERROR: error adding the device '/dev/sdc'" ... it doesn't give a clue. > Note1: the filesystem has to be mounted > Note2: the medatada will be in raid1, the data in raid0 > If you shutdown the system, at the reboot you should "scan" all the > device in order to find the btrfs ones > > # find the btrfs device > btrfs device scan This must be done at every boot? If so, where is recommended, in rc.local? > # if you try to mount snapshot-3 directly, you fail because this > # snapshot is not under the root of the btrfs filesystem > mount -o subvol=dir-1/snapshot-3 /dev/sdb /media/backup # -> error This is how I'd understood it, but when creating a subvolume in the root and putting a snalshot into it, it seems to make a further subvolume (or directory) with a redundant name. This would not be under the root, and may not be mountable? > Which kenel version debian testing uses ? 2.6.32-5-amd64 with Debian patches. > btrfs filesystem snapshot / /snapshot-$(date +"%Y-%m-%d") Oh thank you.