rewriting.. using raid10 or raid01 you will have problems if you lose 2 drives too... if you lose two raid 1 devices you loose raid 1... see: disks=4 RAID 1+0 raid1= 1-2(A) ; 3-4(B); 5-6(C) raid0= A-B-C if you lose (A,B or C) your raid0 stop RAID 0+1 raid0= 1-2-3(A) ; 4-5-6(B) raid1= A-B if you lose (1,4 OR 1,5 OR 1,6 OR 2,4 OR 2,5 OR 2,6 OR 3,4 OR 4,5 OR 4,6) your raid0 stop using raid1+0 or raid0+1 you can't lose two disks... 2011/1/31 Roberto Spadim <roberto@xxxxxxxxxxxxx>: > do you have a faster array using raid0+1 or raid1+0? > > 2011/1/31 Roberto Spadim <roberto@xxxxxxxxxxxxx>: >> 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 >> > > > > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial > -- 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
