From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay3-d.mail.gandi.net ([217.70.183.195]:48113 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753444AbaDFJZt (ORCPT ); Sun, 6 Apr 2014 05:25:49 -0400 From: =?ISO-8859-1?Q?Sw=E2mi?= Petaramesh To: Hugo Mills Cc: Duncan <1i5t5.duncan@cox.net>, linux-btrfs@vger.kernel.org Subject: Re: BTRFS setup advice for laptop performance ? Date: Sun, 06 Apr 2014 11:24:02 +0200 Message-ID: <2131050.Gsdb2GJxUb@tethys> In-Reply-To: <20140405141340.GT7442@carfax.org.uk> References: <2692878.dRG1K49eOP@fnix> <12471892.pAn1KAtSS4@tethys> <20140405141340.GT7442@carfax.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart33258395.OsKD4pIrKs"; micalg="pgp-sha1"; protocol="application/pgp-signature" Sender: linux-btrfs-owner@vger.kernel.org List-ID: --nextPart33258395.OsKD4pIrKs Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" Hi people :-) Le samedi 5 avril 2014 15:13:40 Hugo Mills a =E9crit : >=20 > - I'm not aware, particularly, of any major differences between > noatime and relatime in performance on btrfs. (But I may be wrong > there). It's especially noticeable at first boot in a given day, as "relatime" = will=20 have atimes updated once a day. I've noticed that the 1st boot on any given day can be up to 3-4 times = longer=20 on a BTRFS with "relatime" compared to a btrfs with "noatime". This is=20= especially true if snapshots have recently been made. > - Given Duncan's discussion of the performance of the semantic > desktop, I would suggest turning it off *temporarily* to see if it= > really is where the difficulty lies. I'm afraid that this would turn my email off (I used Kmail and it's bac= king=20 store is Akonadi, and non, I don't want to change MUA), and I can't rea= lly=20 live long without it ;-) > (maybe delete the database and rebuild it regularly? I'm not considering deleting the database. It contains about 1GB of my = email=20 archive and I've no clue about how I could possibly export and reimport= it.=20 The way the Kmail apps use the Akonadi backing store is somewhat tricky= ... > mark parts of it nodatacow? I woud be allright about trying "nodatacow", but it's totally unclear t= o me=20 what impact this can have on snapshots ? Will "nodatacow" defeat snapshots, allowing data to change in snapshots= ? OTOH will snapshots force datacow to happen, defeating the purpose of=20= nodatacow ? As I don't want to break my DB, I won't use nodatacow until I'm sure ab= out the=20 consequences... > maybe autodefrag helps? I've always used autodefrag... Plus I perform manual defrags more often= than=20 in Windows :-/ > maybe it's something simple > the authors of the database can change?). I'm not going to expect KDE people to change anything aytime soon upon = users=20 requests. Some very *SIMPLE* bugs confirmed by dozens of users have sta= yed in=20 their bug tracker for years. KDE bugs stay until somedays God decides to fix one. If ever. > If you truly find btrfs unusable -- which you've said at various > points in the past -- then I'm not going to suggest that you keep > using it. Maybe something else is genuinely better for you. Every 9 months or so I reads reports or reviews or the BTRFS wiki stati= ng that=20 performance and stability of BTRFS have dramatically improved. Then I r= ead=20 everyting I can about new mkfs or btrfstune options, advice, best mount= =20 options, the wiki, and give it a try. Typically a couple months later my machines slow down to the point wher= e I=20 come and start complaining here. Usually 2 more months and I'm back either to ext4 or ZFS, depending on = the=20 machine's specific usage pattern... I still think that BTRFS *should* be very promising *if* its developper= s can=20 fix the recurring performance issues and make it truly usable =AB for b= asic=20 boring office use =BB which is currently typically my case on my laptop= s, and I'm=20 no benchmark (or maybe a human one ?) and I can say that currently, BTR= FS is=20 *not* adapted for a KDE desktop running KMail and Firefox - but if it a= int' no=20 good at this very basic usage, well what is it good at ? I'm not ranting because I love to shoot BTRFS down in flames, but becau= se I'd=20 love to be able to keep it on my system this time, and forget it, and n= ot to=20 reformat everything again in a month or so (as soon as I will tell myse= lf : =AB=20 Well, the improvements promised by kernel 3.14 are still far behind my=20= usability needs =BB)... Kind regards. =2D-=20 Sw=E2mi Petaramesh http://petaramesh.org PGP 907= 6E32E --nextPart33258395.OsKD4pIrKs 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 v2.0.22 (GNU/Linux) iD8DBQBTQR1JL8JcHZB24y4RAo/XAKDEw9iIZ1w2DMqwcmOMevtWv27kPwCfRMdg A6NSKKwBAOLk+cCgnLynktc= =bmK5 -----END PGP SIGNATURE----- --nextPart33258395.OsKD4pIrKs--