Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030510AbWLPA6b (ORCPT ); Fri, 15 Dec 2006 19:58:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030508AbWLPA6a (ORCPT ); Fri, 15 Dec 2006 19:58:30 -0500 Received: from sbcs.cs.sunysb.edu ([130.245.1.15]:37081 "EHLO sbcs.cs.sunysb.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030504AbWLPA6a (ORCPT ); Fri, 15 Dec 2006 19:58:30 -0500 Date: Fri, 15 Dec 2006 19:58:26 -0500 (EST) From: Nikolai Joukov X-X-Sender: kolya@compserv1 To: David Lang cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [ANNOUNCE] RAIF: Redundant Array of Independent Filesystems In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1860 Lines: 38 > > We have designed a new stackable file system that we called RAIF: > > Redundant Array of Independent Filesystems. > > > > Similar to Unionfs, RAIF is a fan-out file system and can be mounted over > > many different disk-based, memory, network, and distributed file systems. > > RAIF can use the stable and maintained code of the other file systems and > > thus stay simple itself. Similar to standard RAID, RAIF can replicate the > > data or store it with parity on any subset of the lower file systems. RAIF > > has three main advantages over traditional driver-level RAID systems: > > this sounds very interesting. did you see the paper on chunkfs? > http://www.usenix.org/events/hotdep06/tech/prelim_papers/henson/henson_html/ I saw Val at OSDI right before this HotDep talk and sure, I have seen the paper :-) > this sounds as if it may be something that you would be able to make a > functional equivalent to chunkfs with your raid0 mode. I also have this feeling. RAIF0 is similar to chunkfs and allows more flexibility. Not only RAIF can stripe the data on many small local file systems (possibly located on multiple drives) but also can stripe the data on remote file systems. In addition, it can keep the parity, use per-file-type storage policies etc. However, such a configuration would mean lots and lots of lower file systems ( = branches = chunks). I am afraid that in this case RAIF's performance would be not so great due to VFS API restrictions for operations like lookup. Nikolai. --------------------- Nikolai Joukov, Ph.D. Filesystems and Storage Laboratory Stony Brook University - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/