From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Evans Subject: Re: Idea for new RAID type - background extended recovery information Date: Sat, 12 Dec 2009 19:47:58 -0800 Message-ID: <4877c76c0912121947m42a62a61y2b2a4a0a74b4d5e1@mail.gmail.com> References: <4877c76c0912090106i684924edn7915c6609ab574f5@mail.gmail.com> <1260602531.7209.10.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: <1260602531.7209.10.camel@localhost> Sender: linux-raid-owner@vger.kernel.org To: Kasper Sandberg Cc: Mikael Abrahamsson , linux-raid List-Id: linux-raid.ids On Fri, Dec 11, 2009 at 11:22 PM, Kasper Sandberg wrote: > On Wed, 2009-12-09 at 11:53 +0100, Mikael Abrahamsson wrote: >> On Wed, 9 Dec 2009, Michael Evans wrote: > > while this could work, i would personally far rather see raid6 gain all > the recovery/sanity options possible. raid6 has multiple copies of the > same data, and as long as you have >2 copies, you can begin to look at > all the data sets, and with a pretty good probability weed out the bad > set. > While I would like to have a layer that any storage use, including other raid levels, could reside within. Imagine how much smarter raid6 could be if it already knew in advance which stripes had gone bad? Or if files older than a few seconds could also gain an additional 'bad sector' survival; allowing the loss of whatever normal raid tolerances plus a bad sector or two. It would not be required, but I believe it would be a good way of adding assurance to long-term storage segments. I implore you to comment on the original suggestion, or my reply to his reply as well.