2011-06-15 (ì), 08:51 +0200, Keld JÃrn Simonsen: > On Wed, Jun 15, 2011 at 11:02:00AM +0900, Namhyung Kim wrote: > > If @conf->far_offset > 0, there is only 1 stripe so that we can treat > > the array same as 'near' arrays. > > does it also work with more than 2 copies - eg 3 copies? > I think the original code just takes the available data blocks with the > lowest address. > Hi, Let me clarify this: AFAIK, 'far offset' array saves redundant data in the diagonally adjacent chunk/disk, so it could be roughly thought as 'raid0' array with reduced size - just ignore redundant chunks here. It was my mistake considering it as 'near' array. :( Therefore, it makes more sense distributing reads over the array based on some criteria - here, the address of starting sector - like RAID0 does. Now I see that the same goes to the 'far copies' array exactly, so the original code is correct. Thanks. -- Regards, Namhyung Kim -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
