From owner-freebsd-fs@FreeBSD.ORG Thu May 17 11:32:45 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 6D0E3106566C for ; Thu, 17 May 2012 11:32:45 +0000 (UTC) (envelope-from nowakpl@platinum.linux.pl) Received: from platinum.linux.pl (platinum.edu.pl [81.161.192.4]) by mx1.freebsd.org (Postfix) with ESMTP id 19F378FC08 for ; Thu, 17 May 2012 11:32:44 +0000 (UTC) Received: by platinum.linux.pl (Postfix, from userid 87) id 8023547E16; Thu, 17 May 2012 13:32:38 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on platinum.linux.pl X-Spam-Level: X-Spam-Status: No, score=-1.5 required=3.0 tests=ALL_TRUSTED,AWL autolearn=disabled version=3.3.2 Received: from [172.19.191.4] (unknown [83.151.38.73]) by platinum.linux.pl (Postfix) with ESMTPA id ED6F447E11 for ; Thu, 17 May 2012 13:32:36 +0200 (CEST) Message-ID: <4FB4E1CC.8030501@platinum.linux.pl> Date: Thu, 17 May 2012 13:32:28 +0200 From: Adam Nowacki User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2.28) Gecko/20120306 Thunderbird/3.1.20 MIME-Version: 1.0 To: freebsd-fs@freebsd.org References: <20120515102206.GA53750@psconsult.nl> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: Mirror of Raidz for data reliability X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 May 2012 11:32:45 -0000 My understanding of this setup is: - there are 2 chasis housing disks, each with a 2 port SAS expander, - there are 2 servers, each with a 2 port SAS HBA (1st port connected to 1st SAS expander, 2nd port connected to 2nd SAS expander). On 2012-05-17 13:17, George Kontostanos wrote: > On Thu, May 17, 2012 at 1:52 PM, George Kontostanos > wrote: >> On Thu, May 17, 2012 at 3:29 AM, Marcelo Araujo wrote: >>> George, >>> >>>> >>>> If you have 2 machines then your best bet would be HAST. >>> >>> >>> So, why use ETHERNET if my Machine can see both JBOD? >> >> I was under the impression that you are talking about 2 different >> physical machines. >> >>>> If you are worried about data replication you can always use lagg with >>>> 2 or more interfaces. >>> >>> >>> It is different than data replication. It is data protection. >> >> Storing the same data in 2 different locations is data protection. >> >> Regards >> > > Ok, after reading more carefully your first post I realized what you > are trying to do. > > 2 Machines, 2 different controllers. Yet interconnected. So, in a way > both machines would be able to see both controllers. > > This is very interesting but there are some implications. > > 1) Suppose you manage to create a mirror consisted by drives on those > different controllers. If you reboot machine #1 machine#2 might panic. > It is not like loosing a drive, here we are loosing a controller. > > 2) Both machines have to be online and the pool has to be mounted > readonly on the standby! You don't want both of them to accidentally > write at the same pool. > > 3) HAST requires tcp to work therefore it is a no go. HAST also works > in the vdev level. Therefore the resources should not be online on the > standby server. > > Good luck, this is certainly very interesting. >