Once upon a time, hw <hw at gc-24.de> said: > Are you saying there is no difference between a RAID1 and a non-raid > device as far as xfs is concerned? Yes. > What if you use hardware RAID? No difference - same result. > When you look at [1], it tells you to specify su and sw with hardware > RAID and says it detects everything automatically with md-RAID. It doesn´t > have an example with RAID1 but one with RAID10 --- however, why would that > make a difference? Because RAID level 1 and RAID level 10 are different. I suggest you read: https://en.wikipedia.org/wiki/RAID#Standard_levels What is called "RAID 10" is really a combination of level 1 and level 0 (which one is higher/lower varies between implementations). > If you read from both > disks in a RAID1 simultaneously, you have to wait out the latency of both > disks before you get the data at full speed, and it might be better to use > stripes with them as well and read multiple parts of the data at the same > time. RAID level 1 has the same data on both drives. You wouldn't be reading the same data from both drives at the same time; reads would be spread between the drives (I know the Linux software RAID tries to keep read load fairly balanced between drives, I assume most hardware RAID implementations do the same). > Oh, ok. How do you know what stripe size was picked by mdadm? It seemd a > good idea to go with defaults as far as possible. Again, RAID level 1 has no stripes. -- Chris Adams <linux at cmadams.net>