From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail1.g1.pair.com ([66.39.3.162]:22028 "EHLO mail1.g1.pair.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750848AbdJaLGQ (ORCPT ); Tue, 31 Oct 2017 07:06:16 -0400 Date: Tue, 31 Oct 2017 12:06:17 +0100 From: Emmanuel Florac Subject: Re: RAID6 + XFS + Application Workload write performance question Message-ID: <20171031120617.015f383c@harpe.intellique.com> In-Reply-To: <8BB5896C-2789-4EB6-9B1B-7DFD4DA9101B@fireeye.com> References: <8BB5896C-2789-4EB6-9B1B-7DFD4DA9101B@fireeye.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/cSZp2Oya3tVwTpk1vM8=e_N"; protocol="application/pgp-signature" Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Kyle Ames Cc: "linux-xfs@vger.kernel.org" --Sig_/cSZp2Oya3tVwTpk1vM8=e_N Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Le Mon, 30 Oct 2017 16:43:15 +0000 Kyle Ames =C3=A9crivait: > OS: CentOS 7.3 > Kernel: 3.10.0-693.2.2.el7.x86_64 > RAID: LSI RAID controller - RAID 6 with 10 disks - Strip Size 128 > (and thus a stripe size of 1MB if I understand correctly) LVM: One > PV, VG, and LV is built on top of the RAID6. The output is below. >=20 > RAID output: > ----------------------------------------------------------------- > DG/VD TYPE State Access Consist Cache Cac sCC Size Name > ----------------------------------------------------------------- > 0/0 RAID6 Optl RW No RAWBD - ON 72.761 TB DATA >=20 > -------------------------------------------------------------------------= --- > EID:Slt DID State DG Size Intf Med SED PI SeSz Model > Sp Type > -------------------------------------------------------------------------= --- > 18:0 35 Onln 0 9.094 TB SAS HDD N N 512B ST10000NM0096 > U - 18:1 39 Onln 0 9.094 TB SAS HDD N N 512B > ST10000NM0096 U - Please note that 10TB disks are using 4k blocks. It's not the culprit here, but using 512b emulated definitely isn't optimal for RAID performance. --=20 ------------------------------------------------------------------------ Emmanuel Florac | Direction technique | Intellique | | +33 1 78 94 84 02 ------------------------------------------------------------------------ --Sig_/cSZp2Oya3tVwTpk1vM8=e_N Content-Type: application/pgp-signature Content-Description: Signature digitale OpenPGP -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAln4WSkACgkQX3jQXNUicVbL5QCg+Y1E/wEgEnunq+5eVBSnM9pc bxAAnj8Aht4YwO4Tw51EAZP37bmhj3R8 =4Jt2 -----END PGP SIGNATURE----- --Sig_/cSZp2Oya3tVwTpk1vM8=e_N--