From owner-freebsd-geom@FreeBSD.ORG Thu May 14 12:11:55 2009 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4B53B106568D for ; Thu, 14 May 2009 12:11:55 +0000 (UTC) (envelope-from edwintorok@gmail.com) Received: from qw-out-2122.google.com (qw-out-2122.google.com [74.125.92.26]) by mx1.freebsd.org (Postfix) with ESMTP id EFBF08FC13 for ; Thu, 14 May 2009 12:11:54 +0000 (UTC) (envelope-from edwintorok@gmail.com) Received: by qw-out-2122.google.com with SMTP id 3so875347qwe.7 for ; Thu, 14 May 2009 05:11:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:received:message-id:date:from :user-agent:mime-version:to:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=hXrFgoPdkYdIGwXSAO3GRg5GrulKLBhJZZfN7AH3HL4=; b=ggbj5L+wBiIZpjTfgJTWjohSrbwyx3t9Mw+4gK9jsro8+70vy5C7/13veEQU43GXCt u6XlVP2jAw+pWBdB8kiykKPNpPEjt7nuzJO+xOQrPgpuxm4ZmJqxdB2duSKBUlDPvwp0 3sEvw9ToU0peZgl4JdDUpFAbLs8ZTsRP/Vsj8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; b=JaqkjE+jQA4OACuiTWZ6H9ddMoPyKVLKD8R7Dhx7KkQo2wEC13xgrOcmZtxg3loORF V1PFBftvdgxmvCF2Nr3QqnfI387CvQY74ICnhb9McM/Q5kWDddTZhPBhIf0LCtpGAF+k dWerAl1tOa4wprNpCb6Rx4/Lvw5qgJdU0+6hs= Received: by 10.220.72.79 with SMTP id l15mr3270205vcj.4.1242303113995; Thu, 14 May 2009 05:11:53 -0700 (PDT) Received: from debian ([79.114.100.143]) by mx.google.com with ESMTPS id 5sm3760378ywd.45.2009.05.14.05.11.52 (version=TLSv1/SSLv3 cipher=RC4-MD5); Thu, 14 May 2009 05:11:53 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by debian (Postfix) with ESMTP id 22FF974F16 for ; Thu, 14 May 2009 15:11:50 +0300 (EEST) Message-ID: <4A0C0A85.50001@gmail.com> Date: Thu, 14 May 2009 15:11:49 +0300 From: =?ISO-8859-1?Q?T=F6r=F6k_Edwin?= User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: freebsd-geom@freebsd.org References: <20090514120030.7F37510656DC@hub.freebsd.org> In-Reply-To: <20090514120030.7F37510656DC@hub.freebsd.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Subject: Re: freebsd-geom Digest, Vol 263, Issue 2 X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 May 2009 12:11:55 -0000 On 2009-05-14 15:00, freebsd-geom-request@freebsd.org wrote: > Send freebsd-geom mailing list submissions to > freebsd-geom@freebsd.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.freebsd.org/mailman/listinfo/freebsd-geom > or, via email, send a message with subject or body 'help' to > freebsd-geom-request@freebsd.org > > You can reach the person managing the list at > freebsd-geom-owner@freebsd.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of freebsd-geom digest..." > > > Today's Topics: > > 1. Re: compatibility with Linux software RAID? (Ivan Voras) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 13 May 2009 14:56:37 +0200 > From: Ivan Voras > Subject: Re: compatibility with Linux software RAID? > To: freebsd-geom@freebsd.org > Message-ID: > Content-Type: text/plain; charset="utf-8" > > Török Edwin wrote: > >> Hi, >> >> Apologies if this has been answered before, but is there a way to access >> (even if just read-only) RAID arrays created by Linux software raid >> tools (mdadm)? >> >> I want to test the new superpages support in FreeBSD 7.2, and do some >> performance comparisons with Linux, problem is all my data is on a >> RAID10 array. >> > > RAID is not the only problem you have - how will you access the data? > FreeBSD's ext2 file system driver isn't nearly as good for any kind of > realistic performance testing - you'd probably need to test Linux with > extX and FreeBSD with UFS2. > I can test FreeBSD booted with superpages enabled vs FreeBSD booted without superpages enabled. You're right that comparing FreeBSD w/ Linux FS vs. Linux w/ Linux FS is not fair. I could copy the data to a temporary ramfs storage, and test from there to eliminate filesystem differences. (not taking the time needed to copy the data into account). > >> Also if gmirror does support the above, is there a way to tell it to >> treat the disks as readonly? >> > > Both gmirror and gstripe can work in a sort of "on-the-fly" mode, > without actually committing any configuration to the drives (see the > "create" command in both). In theory, you could use gmirror and gstripe > with exactly the same parameters as you did in Linux to reconstitute > your data. You'll also probably need gnop to align data before using > gmirror and gstripe. Of course, only do this if you're completely sure > what you're doing and know how RAID10 is physically implemented. > Thanks, I'll do some experiments in a VM first, and if it all works I'll move on to testing with the real drives. Best regards, --Edwin