In general, the speed of a raid array is limited by the speed of the slowest drive. This is why if one drives gets "wonky", the array degrades down to the speed of the slowest drive. If you look at statistically evenly distributed IO, this make sense. After all, each drive will get even numbers of reads, so the read rate of the slowest drive will predominate read overhead. With writes, each drive gets the same number of writes, so the same rules apply. This logic falls apart with mirrors where the raid control layer can choose to aim IO at the least busy drives, but you said you were running raid-5. So in your case, replacing a drive with a faster drive is just fine. Doug Dumitru On Mon, Feb 6, 2012 at 11:54 AM, wilsonjonathan <piercing_male@xxxxxxxxxxx> wrote: > > I was just wondering a quick question... If a system had a failed > 1.5Gbps speed sata (out of 3 in a raid 5) and it was replaced with a > 3Gbps speed drive would the difference affect the speed of the raid, or > would it be no different to its original 3 * 1.5Gbps speed. > > I'm curious as to if the speed difference would affect overall speeds as > obviously 2 drives would be running at half the speed of the other > drives. > > -- > 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 -- Doug Dumitru EasyCo LLC -- 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
