From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 836C113877A for ; Wed, 13 Aug 2014 02:10:00 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 554E6E08BB; Wed, 13 Aug 2014 02:09:40 +0000 (UTC) Received: from mail-lb0-f182.google.com (mail-lb0-f182.google.com [209.85.217.182]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 1F2ABE0884 for ; Wed, 13 Aug 2014 02:09:36 +0000 (UTC) Received: by mail-lb0-f182.google.com with SMTP id z11so7551963lbi.41 for ; Tue, 12 Aug 2014 19:06:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nileshgr.com; s=google; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=jCeODjwQkTYIeILMCkN+MdLGZ5Cu7RfZQyHPMEhFglU=; b=NZU38z/gnbDADWPEZcp9Zfp8dDz03RxVxLOF5xQAnyg9ZjkOeYwcB4SLnlk+375hFW c2Q71iLLrG9WpCmDMB7IlfcC+g+5TtCq0eHwkbq35VtZg2JhrwoLODyGtUBIog+gs53H 01FePz9gtUlbJpcrK4MQkxrPyPXqxVpWfHis8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=jCeODjwQkTYIeILMCkN+MdLGZ5Cu7RfZQyHPMEhFglU=; b=BxHycZ8LIDzC+nw22RWljf+el3o0tD//3sRQAdsJiMqlbNBYxOUIUp/Be8YBckFua4 L01DYeQEbW98x0Eg7ipUzE0sGRuItvj10HeGbvwB4RCaMiiXEJyDD0yY+f7FHUgb5kRa m9PXWOp5eDOgj+ZcgjkyOOuUx6cku+D1f+RzYMbohfAQvAqibAbeDJ7PP43Q9+yzDs3u 0BIHHYQ0L6P6mULufjQMCwN8UUyMJLE/jFjlr92UmZMLdEwR1HmwqXaUklr/m/Oldm10 dm5+qreszpEUKz9ARWxYXqrLf4KPQK/Mfq2AkyC3njhhzQsxImsOXWTn7uJvVnuKnWey IZ8w== X-Gm-Message-State: ALoCoQma+OGZXcPJ9r9V1HRtNaR5Hs7TInYTcCsWq7H/I+1uzUDz8+Mw7cnFgqB4upUiMgghjqwi Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 X-Received: by 10.112.35.97 with SMTP id g1mr1365688lbj.20.1407895201818; Tue, 12 Aug 2014 19:00:01 -0700 (PDT) Received: by 10.112.253.162 with HTTP; Tue, 12 Aug 2014 19:00:01 -0700 (PDT) In-Reply-To: <20140812201025.51c97196@marcec> References: <20140812201025.51c97196@marcec> Date: Wed, 13 Aug 2014 07:30:01 +0530 Message-ID: Subject: Re: [gentoo-user] Portage metadata cache backend: sqlite or not? From: Nilesh Govindrajan To: Gentoo User Mailing List Content-Type: text/plain; charset=UTF-8 X-Archives-Salt: 2c05cfb0-f586-4ada-b7c8-bd533f3a0a1f X-Archives-Hash: ed7ce1d25a5df5f9a9da14167ecca50a On Tue, Aug 12, 2014 at 11:40 PM, Marc Joliet wrote: > Hi list > > For the longest time I've had portage configured to use the sqlite metadata > cache backend as per an old HOWTO [0], however, I thought that it would be a > good idea to revisit that decision. > > Now apparently, this was supposed to speed up portage, although even that > depends. For instance, [0] says that the metadata_overlay backend is faster on > fast storage; since all of portage is on an SSD, that ought to be the case for > me. However, [0] is pretty outdated, so I don't really know, and don't have any > comparison. > > In addition to that, I don't explicitly make use of the sqlite metadata cache, > that is, I don't (consciously) use any software that accesses those DBs, except > for eix (except for overlays, where one would need to run "emerge --regen" > first, which is *ssssslllllloooowwwww*), which can make use of them if > CACHE_METHOD is set appropriately; this speeds up eix-update considerably. > > Does anybody here have experience with this, or a recommendation? I tried > switching to the default cache method temporarily to see how things perform, > and "emerge @world -uDNva" slowed down by about 30 seconds, so preliminary > results point to sticking with sqlite (although it could at least partly be a > btrfs performance regression in Linux 3.15, since there have been several reports of > those, and several fixes slated for 3.16). Anyway, I'm also unsure of unintended > consequences, or other settings I might have to change, too. > > Also, does anybody have any performance data and/or experience on using btrfs > with compression in this context? > > [0] http://www.gentoo-wiki.info/TIP_speed_up_portage_with_sqlite > > Greetings, > -- > Marc Joliet > -- > "People who think they know everything really annoy those of us who know we > don't" - Bjarne Stroustrup Having tried this feature, I'd advise against it. It takes long time to generate metadata after sync and not really that advantageous. Also eix has it's own issues in this mode.