From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from frost.carfax.org.uk ([85.119.82.111]:42078 "EHLO frost.carfax.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755093AbaICHdL (ORCPT ); Wed, 3 Sep 2014 03:33:11 -0400 Date: Wed, 3 Sep 2014 08:33:05 +0100 From: Hugo Mills To: Duncan <1i5t5.duncan@cox.net> Cc: linux-btrfs@vger.kernel.org Subject: Re: Btrfs-progs-3.16: fs metadata is both single and dup? Message-ID: <20140903073305.GH18897@carfax.org.uk> References: <20140902121349.GF18897@carfax.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bFsKbPszpzYNtEU6" In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: --bFsKbPszpzYNtEU6 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 03, 2014 at 04:53:39AM +0000, Duncan wrote: > Hugo Mills posted on Tue, 02 Sep 2014 13:13:49 +0100 as excerpted: >=20 > > On Tue, Sep 02, 2014 at 12:05:33PM +0000, Holger Hoffst=E4tte wrote: > >> So where does the confusing initial display come from? [I] don't > >> remember ever seeing this with btrfs-progs-3.14.2. > >=20 > > Your memory is faulty, I'm afraid. It's always done that -- at > > least since I started using btrfs, several years ago. > >=20 > > I believe it comes from mkfs creating a trivial basic filesystem > > (with the single profiles), and then setting enough flags on it that the > > kernel can bootstrap it with the desired chunks in it -- but I may be > > wrong about that. >=20 > Agreed. It's an artifact of the mkfs.btrfs process and a btrfs fi df on= =20 > a new filesystem always seems to have those extra unused single profile= =20 > lines. >=20 > I got so the first thing I'd do on first mount was a balance -- before=20 > there was anything actually on the filesystem so it was real fast -- to= =20 > get rid of those null entries. Interesting. Last time I tried that (balance without any contents), the balance removed *all* the chunks, and then the FS forgot about what configuration it should have and reverted to RAID-1/single. I usually recommend writing at least one 4k+ file to the FS first, if it's bothering someone so much that they can't let it go. Hugo. > Actually, I had already created a little mkfs.btrfs helper script that=20 > sets options I normally want, etc, and after doing the mkfs and balance= =20 > drill a few times, I setup the script such that if at the appropriate=20 > prompt I give it a mountpoint to point balance at, it'll mount the=20 > filesystem and immediately run a balance, thus automating things and=20 > making the balance part of the same scripted process that does the=20 > mkfs.btrfs in the first place. >=20 > IOW, those null-entry lines bother me too... enough that even tho I know= =20 > what they are I arranged things so they're automatically and immediately= =20 > eliminated and I don't have to see 'em! =3D:^) >=20 --=20 =3D=3D=3D Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk= =3D=3D=3D PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- Never underestimate the bandwidth of a Volvo filled --- =20 with backup tapes. =20 --bFsKbPszpzYNtEU6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIVAwUBVAbEMFheFHXiqx3kAQIM/Q/9GzYpLICW08J0JU2WRS8CK5Z2u88z6n+h VyF1hgclqRcwNJB+N+iMK0A9Z/ouNm902zprrKokvLNGu5uraOSGFpCjmVu/XOFm MBGhVP4XvRwQgJ0ZgKGEKsQiayex+ISNLsmeHjM7uA4qZfjbgfIO9GQOKs3I+E+a cemxwjQigjpn/SJsnbK/5OyL/nx4hgzuivrVc2911KwozANaQpXu1XQBLnBAai+A oPhbpci6xUJwGZOz8I9lOZaLMyQ9yWADczqO+J5lLgz1oo2uA8w+VKx9zOC1y0He nIArJ4WpATsZRdtZ6oM0A7zw4I3cUHT5/yLkKScloVRGrg8YWsFBwYUSR2yXc48v A6Yp0Jv9naeQ5RFEFEx8juXSvuzsYCnugsCSyXfLJ50Bne3NyoKfOaJAhu3UrKN5 q3GzhkmbeOy9SEDH22hg9KmeINtsB668ITh6TyyhJmWfEmt8+jDj4aI/5R/GVzzc XhoeaSOHqyqy8qp45cqePz2RJ4OW5078xYzm/lJC0PeHtieBo9DJQoikPw+nZhnf t9zhJ/zkwTJH7Mod0FfCPsK6kJxvbV1ayW148CAi9vpp0aMIXXo11tYZR9SbG3f/ DNFlfCuqYe32FPqhuQv1JBk/O0FzEa120p4Ze9j0GOShKhdkzQd/tvGknNH/BO7F M3XGuzvbhZw= =CMuk -----END PGP SIGNATURE----- --bFsKbPszpzYNtEU6--