From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arne Jansen Subject: Re: [RFC] Subvolume Quota on-disk structures and configuration Date: Mon, 21 Nov 2011 18:20:07 +0100 Message-ID: <4ECA8847.2080905@gmx.net> References: <4E19611D.2090007@gmx.net> <4ECA7721.3040607@cfl.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-btrfs To: Phillip Susi Return-path: In-Reply-To: <4ECA7721.3040607@cfl.rr.com> List-ID: On 11/21/2011 05:06 PM, Phillip Susi wrote: > On 7/10/2011 4:21 AM, Arne Jansen wrote: >> btrfs qgroup limit [--exclusive] |none >> >> >> btrfs qgroup limit 10g /usr >> >> That should be simple enough for the common use case. > > Wouldn't that make the syntax above actually be: > > btrfs qgroup limit [--exclusive] [qgroupid] You don't mean to actually changing the syntax, but adding a better explanation or a more precise usage? > > Since the qgroupid is optional? And the meaning of path depends on > whether or not qgroupid is specified. With qgroupid, path is anywhere > on the fs, but without it, it specifies the path of the implicit > qgroupid, right? > > I also have a question about the interactions with groups of groups. Say > I have 4 subvolumes: 1, 2, 3, and Z. I group the first 3 volumes and > set a limit on them. Now if all 3 volumes share a chunk of space, that > space should only count towards the group once, rather than 3 times. It's just what groups are made for. In your scenario the chunk of space would count only once. Some hopefully better explanation can be found at http://sensille.com/qgroups.pdf Have you already played with the patchset? -Arne > You might think the solution to that is to use the exclusive limits, but > that would mean that any space volume 3 and volume Z share would not be > counted in the group at all. I don't care about volume Z since it is > not part of the group, yet it can influence the used space of the > group. Likewise, if I set an exclusive limit on the group, and then > create snapshot Y from subvol 2, that would significantly reduce the > exclusive charge for the group, and we don't want that. > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html