From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from resqmta-po-11v.sys.comcast.net ([96.114.154.170]:42075 "EHLO resqmta-po-11v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751348AbbCTCe2 (ORCPT ); Thu, 19 Mar 2015 22:34:28 -0400 Message-ID: <550B8732.5000302@comcast.net> Date: Thu, 19 Mar 2015 19:34:26 -0700 From: don fisher MIME-Version: 1.0 To: "linux-btrfs@vger.kernel.org" Subject: Re: nube trying to backup my systems References: <550B5C63.6010401@comcast.net> <550B7CAC.6030005@comcast.net> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 03/19/2015 07:15 PM, Chris Murphy wrote: > On Thu, Mar 19, 2015 at 7:49 PM, don fisher wrote: >> My rot >> is mounted at /usr11. I tried: >> >> UUID=26d63d99-92f4-4a49-878b-236f5e88af69 /usr11/srv btrfs >> subvol=usr11/srv 0 0 >> >> but /usr11/srv did not mount. I replaced the number and it did mount. Would >> like to use string like you suggested since they are more understandable. Do >> you see what I did wrong? > > Use 'btrfs subvolume list -a' like I suggested and use that path minus > any leading /. Chances are the path to the subvolume srv is just srv, > in which case it should be subvol=srv > >> Any thoughts on stability of the IDs across boots? > > They're completely reliable between reboots and renames. They're > assigned at creation, and either btrfs sub create or btfs sub snap > creates subvolumes. Thanks. I will try that. How does the mount distinguish between /srv and /usr11/srv if the subvol=srv is the same for both? It appears to work, for when I do a df the sizes are different. I guess it can tell from the UUID of / as opposed to that of /usr11. I missed that one completely. /dev/sdc2 20972544 6117628 14641012 30% /srv /dev/sdb2 20972544 9492892 11112580 47% /usr11/srv I would still like to know why we need to mount the subvolumes at all. I tried to dismount one of the subvolumes mounted on / and got a: umount: /var/log: target is busy message, so could not test to /var/log access without a mount. It is easy to access /usr11/var/log without it being mounted. Again, why mount it? I understood mounting partitions, because that was the only access. But the appears to be two access channels here. I made another openSuse system on a 2.5" USB drive. I will use it for the test tomorrow when more of my neurons are firing. Thanks Don