Once upon a time, hw <hw@xxxxxxxx> 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@xxxxxxxxxxx>
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
https://lists.centos.org/mailman/listinfo/centos
