From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from frost.carfax.org.uk ([85.119.82.111]:41364 "EHLO frost.carfax.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750956AbaCGICQ (ORCPT ); Fri, 7 Mar 2014 03:02:16 -0500 Date: Fri, 7 Mar 2014 08:02:13 +0000 From: Hugo Mills To: Michael Russo Cc: linux-btrfs@vger.kernel.org Subject: Re: ENOSPC errors during raid1 rebalance Message-ID: <20140307080213.GC6318@carfax.org.uk> References: <20140303183911.GL13899@carfax.org.uk> <73124688-5EDF-4DB5-AC9E-9F365397DD28@colorremedies.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Md/poaVZ8hnGTzuv" In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: --Md/poaVZ8hnGTzuv Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Mar 07, 2014 at 01:13:53AM +0000, Michael Russo wrote: > Duncan <1i5t5.duncan cox.net> writes: >=20 > > But if you're not using compression, /that/ can't explain it... > >=20 >=20 > Ha! Well while that was an interesting discussion of fragmentation, > I am only using the default mount options here and so no compression.=20 > The only reason I'm really even looking at the fragmentation=20 > issue is because running the defragment (with varying sizes of > "-t" which I'm not sure why that's even necessary) seemed > to force btrfs to move segments around and let me rebalance > more block groups. I don't even care if the files are defragged, > I just want them all in the RAID1 profile. Hopefully if I move > each file out to some other FS like /dev/shm and then back > it will work, I just gotta hack a script together to do so. I _think_ the problem here is that there may have been some extents created during the conversion which were over 1 GiB in size (or at least which run across two or more chunks). This causes problems, because there's nowhere that they can be written to by the balance -- which preserves extents -- because none of the allocation units (chunks) are big enough. The defrag operation, by its nature, _doesn't_ preserve extents, and thus can act to break up the large extents, making it possible to balance the chunks that the offending extents live on. Hugo. --=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 --- If the first-ever performance is the premi=E8re, is the --- = =20 last-ever performance the derri=E8re? = =20 --Md/poaVZ8hnGTzuv Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIVAwUBUxl9BVheFHXiqx3kAQIauxAAvOr6Bj43BuR9S3FGM5ttlKkXYNrOM+VH ofcRMbjEq91wE1WPmKwRfi/2lOCSMdmpd8KpZUzuikx7BDi0q4UqzXYtSj6Mg2c1 3X//pSmKA0VhRAHGP5LI16RDUb+7WHWNd/oZqOSnYgljpU1TwLSlmG+Ktg1KlElW w5iDBNRjEnJVRcZ/GPTXvugmhPlcxmjMR8pnBCK+4x6H8JQ+n6fmDjutlu37ES8j Cl9kNncKxCHp8PkJKFidLT51g2Qu40J2HGZTEicCAPMa/iyWlcR2O/VdrASYCUn7 j0+I3Mjzqo73+Uqd5Vym5G2ma+GtS14ihBFdtKTUfHAIaoI+Dkgfh8UAv1Q6eGTM gR/tSz5u7wKGEWcYy9vA0zoEAqjpx2TVjn9e4Kpj4gyvVTQlvs6LU2qE9qZkd79i F9KnHf9LW7seaeQ0xnuzc/F8o2CrCpB4I71NZ1MbJ75y2i0Gdp0YzV+AFK8gQBFz THbd5hGPgN+v835rxG57cBRCM5YIarLYwnxizSff+X9f2uXi1XNnRPBCSE7JLT8Q YvH3nIwVErNWjfs18zgX7LstKlsPzZLFTbVAT5hPsAV4aU1ZZZOBllCXy2Q4njVh D1XHoyxJsGFPCmaZO5ZcvTAK0PwjsTijBwK0TTodDAEHPNIurRrUkKbsUbHwIt0V FZPgDSEvfsA= =7Y9d -----END PGP SIGNATURE----- --Md/poaVZ8hnGTzuv--