On Wed, Sep 26, 2012 at 09:59:42AM +0100, John Robinson wrote: > On 26/09/2012 09:28, keld@xxxxxxxxxx wrote: > [...] > >I also understand it now, I think. raid10,f2 with 4 disks cannot in the > >current implementation > >survive 2 failing disks. > > It can, but only two non-adjacent discs. With 4 drives sda-sdd, than > means you can only lose both sda and sdc, or sdb and sdd. Agree > >We have discussed earlier how to implement raid10,far that would mean > >better survival chances with more disks failing. This is not implemented > >yet. > > No, but even if/when it is, there will still be some combinations of two > discs that you cannot afford to lose. The layout change to try to > improve redundancy will not be generic, as it doesn't work for an odd > number of discs, so the existing layout would have to be retained as an > option. Well, at least for backward compatibility we need an option for the current layout. For odd number of disks, I do think we can improve the chances for more failing disks, as discussed earlier. best regards keld -- 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
