On 04/05/2011 01:07, Liam Kurmos wrote:
Hi, I've been testing mdadm (great piece of software btw) however all my test show that reading from raid1 is only the same speed as reading from a single drive. Is this a known issue? or is there something seriously wrong with my system? i have tried v2.8.1 and v.3.2.1 without difference and several benchmarking methods.
This is a FAQ. Yes, this is known. No, it's not an issue, it's by design - pretty much any RAID 1 implementation will be the same because of the nature of spinning discs. md RAID 1 will serve multiple simultaneous reads from the different mirrors, giving a higher total throughput, but a single-threaded read will read from only one. If you want RAID 0 sequential speed at the same time as RAID 1 mirroring, look at md RAID 10, and in particular RAID 10,f2; please see the excellent documentation and wiki for more details.
Cheers, John. -- 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
