hum that's right, but not 'increase' (only if you compare raid0+1 betwen raid1+0) using raid1 and after raid0 have LESS point of fail between raid 0 and after raid 1, since the number of point of fail is proportional to number of raid1 devices. 2011/1/31 Robin Hill <robin@xxxxxxxxxxxxxxx>: > On Mon Jan 31, 2011 at 01:00:13PM -0200, Roberto Spadim wrote: > >> i think make two very big raid 0 >> and after raid1 >> is better >> > Not really - you increase the failure risk doing this. With this setup, > a single drive failure from each RAID0 array will lose you the entire > array. With the reverse (RAID0 over RAID1) then you require both drives > in the RAID1 to fail in order to lose the array. Of course, with a 4 > drive array then the risk is the same (33% with 2 drive failures) but > with a 6 drive array it changes to 60% for RAID1 over RAID0 versus 20% > for RAID0 over RAID1. > > Cheers, > Robin > -- > 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 > -- Roberto Spadim Spadim Technology / SPAEmpresarial -- 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
