From owner-freebsd-questions@FreeBSD.ORG Thu Feb 20 20:45:29 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 0DC7C3BD for ; Thu, 20 Feb 2014 20:45:29 +0000 (UTC) Received: from email2.allantgroup.com (email2.emsphone.com [199.67.51.116]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id ABD671D24 for ; Thu, 20 Feb 2014 20:45:28 +0000 (UTC) Received: from dan.emsphone.com (dan.emsphone.com [172.17.17.101]) by email2.allantgroup.com (8.14.7/8.14.7) with ESMTP id s1KKjQlI091780 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 20 Feb 2014 14:45:26 -0600 (CST) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (smmsp@localhost [127.0.0.1]) by dan.emsphone.com (8.14.7/8.14.6) with ESMTP id s1KKjQ9k049985 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 20 Feb 2014 14:45:26 -0600 (CST) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.8/8.14.7/Submit) id s1KKjQlu049984; Thu, 20 Feb 2014 14:45:26 -0600 (CST) (envelope-from dan) Date: Thu, 20 Feb 2014 14:45:26 -0600 From: Dan Nelson To: Steve Burton Subject: Re: iSCSI Backing store Message-ID: <20140220204526.GE80443@dan.emsphone.com> References: <530661A6.1030606@sliderule.demon.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <530661A6.1030606@sliderule.demon.co.uk> X-OS: FreeBSD 9.2-STABLE User-Agent: Mutt/1.5.22 (2013-10-16) X-Virus-Scanned: clamav-milter 0.98.1 at email2.allantgroup.com X-Virus-Status: Clean X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (email2.allantgroup.com [172.17.19.78]); Thu, 20 Feb 2014 14:45:26 -0600 (CST) X-Spam-Status: No, score=-3.9 required=5.0 tests=ALL_TRUSTED,BAYES_00, RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on email2.allantgroup.com X-Scanned-By: MIMEDefang 2.73 Cc: FreeBSD Questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 20 Feb 2014 20:45:29 -0000 In the last episode (Feb 20), Steve Burton said: > I'm trying to familiarize myself with the iSCSI implementation in FreeBSD > 10 REL. I have made a target containing two LUNs which are backed by two > files on my test server (redundant PC). This all worked well though it > took ages to make the files using dd. > > dd if=/dev/zero of=/targets/target0-0 bs=512 count=31250000 > > My first question is, is there a better and quicker way to make the > backing store files? A 512-byte blocksize is suboptimal; you're spending most of your time just processing the read/write syscalls at that size. There isn't much benefit to using a blocksize over 64k, but using 1m does make it easy to calculate the count for large volumes :) > My second question relates to making iSCSI LUNs using a disk volume. I > have a second (empty) hard drive. Is it possible to just use the disk as > backing store for iSCSI? I don't see why not. -- Dan Nelson dnelson@allantgroup.com