From owner-freebsd-current@FreeBSD.ORG Thu Dec 2 14:41:53 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3EF5416A4CF for ; Thu, 2 Dec 2004 14:41:53 +0000 (GMT) Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7083743D62 for ; Thu, 2 Dec 2004 14:41:52 +0000 (GMT) (envelope-from andre@freebsd.org) Received: (qmail 27464 invoked from network); 2 Dec 2004 14:32:53 -0000 Received: from dotat.atdotat.at (HELO [62.48.0.47]) ([62.48.0.47]) (envelope-sender ) by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP for ; 2 Dec 2004 14:32:53 -0000 Message-ID: <41AF29AC.6030401@freebsd.org> Date: Thu, 02 Dec 2004 15:41:48 +0100 From: Andre Oppermann User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8a5) Gecko/20041122 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Scott Long References: <41AE3F80.1000506@freebsd.org> In-Reply-To: <41AE3F80.1000506@freebsd.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit cc: hackers@freebsd.org cc: "current@freebsd.org" Subject: Re: My project wish-list for the next 12 months X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Dec 2004 14:41:53 -0000 Scott Long wrote: > 5. Clustered FS support. SANs are all the rage these days, and > clustered filesystems that allow data to be distributed across many > storage enpoints and accessed concurrently through the SAN are very > powerful. RedHat recently bought Sistina and re-opened the GFS source > code, so exploring this would be very interesting. There are certain steps that can be be taken one at a time. For example it should be relatively easy to mount snapshots (ro) from more than one machine. Next step would be to mount a full 'rw' filesystem as 'ro' on other boxes. This would require cache and sector invalidation broadcasting from the 'rw' box to the 'ro' mounts. The holy grail of course is to mount the same filesystem 'rw' on more than one box, preferrably more than two. This requires some more involved synchronization and locking on top of the cache invalidation. And make sure that the multi-'rw' cluster stays alive if one of the participants freezes and doesn't respond anymore. Scrolling through the UFS/FFS code I think the first one is 2-3 days of work. The second 2-4 weeks and the third 2-3 month to get it right. If someone would throw up the money... -- Andre