From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from csamuel.org ([74.50.50.137]:33146 "EHLO csamuel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932712AbaDIKxu (ORCPT ); Wed, 9 Apr 2014 06:53:50 -0400 From: Chris Samuel To: linux-btrfs@vger.kernel.org Cc: Austin S Hemmelgarn , =?ISO-8859-1?Q?Sw=E2mi?= Petaramesh , Duncan <1i5t5.duncan@cox.net> Subject: Re: BTRFS setup advice for laptop performance ? Date: Wed, 09 Apr 2014 20:53:20 +1000 Message-ID: <1748210.42KeASGE2J@quad> In-Reply-To: <5342C00F.8070001@gmail.com> References: <2692878.dRG1K49eOP@fnix> <12471892.pAn1KAtSS4@tethys> <5342C00F.8070001@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart21173548.1mGQha3dTz"; micalg="pgp-sha1"; protocol="application/pgp-signature" Sender: linux-btrfs-owner@vger.kernel.org List-ID: --nextPart21173548.1mGQha3dTz Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" On Mon, 7 Apr 2014 11:11:11 AM Austin S Hemmelgarn wrote: > This is because every other filesystem (except ZFS) doesn't use COW > semantics. There is an interesting article on LWN at the moment (subscriber only f= or the=20 next day or two, but if you can afford it I'd suggest considering subsc= ribing)=20 about the Linux Storage, Filesystem, and Memory Management (LSFMM) Summ= it=20 discussions around the impact of the new Shingle Magnetic Recording (SM= R)=20 drives that may change that. Given these devices are likely to have large sequential write only area= s it's=20 going to make getting existing Linux filesystems to work on them "inter= esting",=20 in the section on Dave Chinners filesystem part of the discussion it sa= ys: # Any of the existing filesystems that do not support copy-on-write (CO= W) # cannot really be optimized for SMR, he said, because you can't overwr= ite # data in sequential zones. That would mean adding COW to ext4 and XFS,= # Chinner said.=20 https://lwn.net/Articles/592091/ There's some background to SMR drives (available to all) from the LSFMM= here: https://lwn.net/Articles/591782/ All the best, Chris =2D-=20 Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC --nextPart21173548.1mGQha3dTz 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 v1.4.14 (GNU/Linux) iQEVAwUAU0UmoI1yjaOTJg85AQKO7QgAk94QoA3I7hxCOxdT1ijNlRcwtJq01D8X KdG0oHyzPloEK2wUuB8ZsFNrQkbDoViGGAjgaW8LMcm7ytGb4BBnQGBjQqtlIMYa 3zLCGFDDXC8LqX3fHGGbBl2S/Hir19LmD5aHEwzJl0WsNOaZRTDkNKsULxaSe5nW lAVlGFgdr0CgBkmMugwY4hfYojs9vGdHzQgbC6mqwDYh1/IddwBfJoB9BTRYjREl aQy/CV6YhNGqo8FN4/ClLB7P47Aki+txy/1lUP/el1sMFnbRzdcgFxftYkONnUIN h1HeG3BQRf/eyr6oBKjMv6zxW4VfjReIUc0bchqlWTMrwF5sUxijwA== =qccp -----END PGP SIGNATURE----- --nextPart21173548.1mGQha3dTz--