From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: suns raid-z / zfs Date: Mon, 18 Feb 2008 15:07:44 +1100 Message-ID: <18361.1168.473685.214133@notabene.brown> References: <20080217160403.GA15710@rap.rap.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Keld Jorn Simonsen on Sunday February 17 Sender: linux-raid-owner@vger.kernel.org To: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Sunday February 17, keld@dkuug.dk wrote: > Hi > > any opinions on suns zfs/raid-z? It's vaguely interesting. I'm not sold on the idea though. > It seems like a good way to avoid the performance problems of raid-5 > /raid-6 I think there are better ways. > > But does it stripe? One could think that rewriting stripes > other places would damage the striping effects. I'm not sure what you mean exactly. But I suspect your concerns here are unjustified. > > Or is the performance only meant to be good for random read/write? I suspect it is mean to be good for everything. But you would have to ask SUN that. > > Can the code be lifted to Linux? I understand that it is already in > freebsd. Does Suns licence prevent this? My understanding is that the sun license prevents it. However raid-z only makes sense in the context of a specific filesystem such as ZFS. It isn't something that you could just layer any filesystem on top of. > > And could something like this be built into existing file systems like > ext3 and xfs? They could have a multipartition layer in their code, and > then the heuristics to optimize block access could also apply to stripe > access. I doubt it, but I haven't thought deeply enough about it to see if there might be some relatively non-intrusive way. NeilBrown > > best regards > keld > - > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html