On Tue, Jan 29, 2008 at 05:07:27PM +0300, Michael Tokarev wrote: > Peter Rabbitson wrote: > > Moshe Yudkowsky wrote: > >> > > > It is exactly what the names implies - a new kind of RAID :) The setup > > you describe is not RAID10 it is RAID1+0. > > Raid10 IS RAID1+0 ;) > It's just that linux raid10 driver can utilize more.. interesting ways > to lay out the data. My understandining is that raid10 is different from RAID1+0 Traditional RAID1+0 is composed of two RAID1's combined into one RAID0. It takes 4 drives to make it work. Linux raid10 only takes 2 drives to work. Traditional RAID1+0 only have one way of laying out the blocks. raid10 have a number of ways to do layout, namely the near, far and offset ways, layout=n2, f2, o2 respectively. Traditional RAID1+0 can only do striping of half of the disks involved, while raid10 can do striping on all disks in the far and offset layouts. I looked around on the net for documentation of this. The first hits (on Google) for mkadm did not have descriptions of raid10. Wikipedia describes raid 10 as a synonym for raid1+0. I think there is too much confusion on the raid10 term, and that also the marveleous linux raid10 layouts is a little known secret beyound maybe the circles of this linux-raid list. We should tell others more about the wondersi of raid10. And then I would like a good reference for describing how raid10,o2 works and why bigger chunks work. 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
