From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from achille.seblu.net ([62.210.204.83]:39798 "EHLO achille.seblu.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751882AbcGQCJb (ORCPT ); Sat, 16 Jul 2016 22:09:31 -0400 Received: from murphy.h.seblu.net (cac94-h02-176-184-25-92.dsl.sta.abo.bbox.fr [176.184.25.92]) (Authenticated sender: seblu) by achille.seblu.net (Postfix) with ESMTPSA id D816750C0093 for ; Sun, 17 Jul 2016 04:09:21 +0200 (CEST) Message-ID: <1468721359.19617.169.camel@seblu.net> Subject: Size reported differently between profiles From: =?ISO-8859-1?Q?S=E9bastien?= Luttringer To: linux-btrfs Date: Sun, 17 Jul 2016 04:09:19 +0200 Content-Type: multipart/signed; micalg="pgp-sha384"; protocol="application/pgp-signature"; boundary="=-0zZuD784itTn6mVEMT1s" Mime-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: --=-0zZuD784itTn6mVEMT1s Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hello, =C2=ABbtrfs fi usage=C2=BB report size differently between single,RAID0,RAI= D1,RAID5,RAID6 and RAID10. The test is done with 2 files of 1.4GiB each on 4x10GiB devices. I used bal= ance to get size between profiles. Data,single: Size:4.00GiB, Used:2.85GiB =C2=A0=C2=A0=C2=A0/dev/sdb =C2=A0=C2=A0=C2=A01.00GiB =C2=A0=C2=A0=C2=A0/dev/sdc =C2=A0=C2=A0=C2=A01.00GiB =C2=A0=C2=A0=C2=A0/dev/sdd =C2=A0=C2=A0=C2=A01.00GiB =C2=A0=C2=A0=C2=A0/dev/sde =C2=A0=C2=A0=C2=A01.00GiB Data,RAID0: Size:8.00GiB, Used:2.85GiB =C2=A0=C2=A0=C2=A0/dev/sdb =C2=A0=C2=A0=C2=A02.00GiB =C2=A0=C2=A0=C2=A0/dev/sdc =C2=A0=C2=A0=C2=A02.00GiB =C2=A0=C2=A0=C2=A0/dev/sdd =C2=A0=C2=A0=C2=A02.00GiB =C2=A0=C2=A0=C2=A0/dev/sde =C2=A0=C2=A0=C2=A02.00GiB Data,RAID1: Size:4.00GiB, Used:2.85GiB /dev/sdb 2.00GiB /dev/sdc 2.00GiB /dev/sdd 2.00GiB /dev/sde 2.00GiB Data,RAID5: Size:6.00GiB, Used:2.85GiB /dev/sdb 2.00GiB /dev/sdc 2.00GiB /dev/sdd 2.00GiB /dev/sde 2.00GiB Data,RAID6: Size:6.00GiB, Used:2.85GiB /dev/sdb 3.00GiB /dev/sdc 3.00GiB /dev/sdd 3.00GiB /dev/sde 3.00GiB Data,RAID10: Size:4.00GiB, Used:2.85GiB /dev/sdb 1.00GiB /dev/sdc 1.00GiB /dev/sdd 1.00GiB /dev/sde 1.00GiB For single,RAID0,RAID10 profiles, the sum of device sizes is equal to total= size. Like total size is the "byte allocated size" for all devices. For RAID1,RAID5,RAID6 profiles, sum of devices sizes is more than the total= size. Looks like the redundancy was subtracted from the total. Like total size is the "profile size allocated". So, why RAID1 and RAID10 are reporting their sizes differently? This confus= e me. Cheers, --=20 S=C3=A9bastien "Seblu" Luttringer https://seblu.net | Twitter: @seblu42 GPG: 0x2072D77A --=-0zZuD784itTn6mVEMT1s Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIUBAABCQAGBQJXiujPAAoJEDwch2Awtl/iuEAPwJywRGDeO/0lxKLOG5jDBjhB JiVrnSTra9PgKuDP+h3Dvla1BwVurur25+CQqnkkFi2kUDmtbXUV+8NrL3SZDlnW feYfkMliIuxcL9WVS0Fy9UBugutRzCFZHIMG22ywTsRUlrgu1RstoAPDrXSi6Bod chtbD7jnutbGQEloGZOPoHxXUAsZuXtGIg+0xSHbH5E6BJWmVmXGqdQED6Xyae9s mgxKHhXhLZhMdWtcMdcv/HfRpqrvD6rEEAoE3TuQ38ETQv+IQbt8U9wBU0UUHLGD GjqCWcUqp6YDfq1OGp6P4t/wHuG7jBD8mzBfsAuzTOm0A6NbYWVuKAWlY0YbGZXR udAzli1b4d/qxQydTH11dsj1ZajRNOyZz1gOC3UpRBEEq17uM1yxBwVodKsKASsI q/vGYZBeZ2K6xpiz7nqARXVnz//mDuqixB52xb2jZpObClq+wKDscS1NZJNIoa9a gsQjMhQvly///yOEOtv727evRlNs/XWY0Ps4lJ/AqFf+H37Dicz9SXYBqZYDM9w3 A4OxL+C4B/1AUN43WPRxghJFFIwoodSx2U4UP5rMAHpWAX+IaQx6TPFsbwrCqk21 hw621X9WFOv09hCDMMgEAFHzWr2MeimQy95WrCCEy+Lqf8I5QIMqL5z2rVWpqFYA y2/zQ+osPg== =sLiU -----END PGP SIGNATURE----- --=-0zZuD784itTn6mVEMT1s--