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 6520B1381F3 for ; Tue, 17 Sep 2013 19:30:42 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 60051E0CE2; Tue, 17 Sep 2013 19:30:35 +0000 (UTC) Received: from mail-bk0-f47.google.com (mail-bk0-f47.google.com [209.85.214.47]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 32201E0C83 for ; Tue, 17 Sep 2013 19:30:33 +0000 (UTC) Received: by mail-bk0-f47.google.com with SMTP id mx12so2370181bkb.34 for ; Tue, 17 Sep 2013 12:30:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=9pgiRCo8dAvl05ADKoTO86MQm93WI0e/ImQMzZtlD0E=; b=ZhbKtdILTYNTURvYbeuyndzVW8HLhvCYohqfU37HXaxWNuogJJ3BEC4DcRXmaCc7ue A/mr6H9bWJBttH4RjmBc4zX6c9AhY1doLGgke+H8FB/MBsTKoNzMIYJHHSDFaI+LOqV9 cfM9X/kdUZ5w5MjcEL5ghUmbZQtXqfJZeWgFIuWk490Sjy5iRUNfet13KjTmZU1kA0p/ gFQCZKhIq2zycAvsM8VpuijKco16ZqtwZJYGaI2ysJiHHAZ2D/xibzXT3yjUYPALPRdh Hq3cf6b4ebCOFJBjpatz5IH6Vcl+PnN7g1rpehksoQvahX9HLKEqMzwL8Cps3uoDF56q qCQg== X-Received: by 10.204.78.8 with SMTP id i8mr17228887bkk.3.1379446232576; Tue, 17 Sep 2013 12:30:32 -0700 (PDT) Received: from [192.168.178.21] (p3E9E696F.dip0.t-ipconnect.de. [62.158.105.111]) by mx.google.com with ESMTPSA id b7sm1921719bkg.1.1969.12.31.16.00.00 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 17 Sep 2013 12:30:32 -0700 (PDT) Message-ID: <5238ADD7.8020700@googlemail.com> Date: Tue, 17 Sep 2013 21:30:31 +0200 From: Volker Armin Hemmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130807 Thunderbird/17.0.8 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 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] ZFS References: <523898A3.7000404@googlemail.com> <2097.1379441483@ccs.covici.com> In-Reply-To: <2097.1379441483@ccs.covici.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Archives-Salt: 352534f2-b7e0-4d42-91fc-c983b8e26be1 X-Archives-Hash: 992233f59131669154c7eeb38c71cf5f Am 17.09.2013 20:11, schrieb covici@ccs.covici.com: > Volker Armin Hemmann wrote: > >> Am 17.09.2013 09:20, schrieb Grant: >>> I'm convinced I need 3-disk RAID1 so I can lose 2 drives and keep >>> running. I'd also like to stripe for performance, resulting in >>> RAID10. It sounds like most hardware controllers do not support >>> 6-disk RAID10 so ZFS looks very interesting. >>> >>> Can I operate ZFS RAID without a hardware RAID controller? >>> >>> >From a RAID perspective only, is ZFS a better choice than conventional >>> software RAID? >>> >>> ZFS seems to have many excellent features and I'd like to ease into >>> them slowly (like an old man into a nice warm bath). Does ZFS allow >>> you to set up additional features later (e.g. snapshots, encryption, >>> deduplication, compression) or is some forethought required when first >>> making the filesystem? >>> >>> It looks like there are comprehensive ZFS Gentoo docs >>> (http://wiki.gentoo.org/wiki/ZFS) but can anyone tell me from the real >>> world about how much extra difficulty/complexity is added to >>> installation and ongoing administration when choosing ZFS over ext4? >>> >>> Performance doesn't seem to be one of ZFS's strong points. Is it >>> considered suitable for a high-performance server? >>> >>> http://www.phoronix.com/scan.php?page=news_item&px=MTM1NTA >>> >>> Besides performance, are there any drawbacks to ZFS compared to ext4? >>> >> do yourself three favours: >> >> use ECC ram. Lots of it. 16GB DDR3 1600 ECC ram cost you less than 170€. >> And it is worth it. ZFS showed me just how many silent corruptions can >> happen on a 'stable' system. Errors never seen neither detected thanks >> to using 'standard' ram. >> >> turn off readahead. ZFS' own readahead and the kernel's clash - badly. >> Turn off kernel's readahead for a visible performance boon. >> >> use noop as io-scheduler. > How do you turnoff read ahead? > set it with blockdev to 8 (for example). Doesn't turn it off. Just makes it none-obstrusive.