P420 configuration performance

[Gwendling]

Hi  all,

I have a question concerning what will best for a rais 5 array utilisation on windows 2012:

is it better, for a performance point of view, to create a single logical drive and create 2 windows partitions or to create 2 logical drive on the smart array P420 ?

thank's in advance.

Gerard

[waaronb · Accepted solution]

On the one hand, if you use OS partitions, you can use the OS tools (like in Windows) to delete a secondary partition and extend the primary into that free space, and it's quick.

If you create two logical drives from an array in the array config util, I think that's a "cleaner" way to go, because you're just presenting two drives to the OS, and you can let the P420 deal with putting each logical drive in a good part of the disk.

You can also create logical drive #1 as a RAID 1+0 (maybe for the OS) and then create a larger local drive #2 as RAID 5. That's assuming the array has at least 4 drives in there... enough for RAID 5 (3 or more) and an even number for RAID 1+0.

You also have the flexibility of doing different stripe sizes if needed (could be a factor in SQL or Exchange if you were fine-tuning things to that level).

You can also use the ACU to delete logical drives and then add that space to another logical drive, or migrate raid levels later on if needed. Then once you've extended the logical drive size, you need to go into the OS and extend the partition to use the new space. That works fine too but takes a little longer, but I think it's worth it.

I didn't always do it that way... I used to just create one big array and then do OS partitioning, but with the latest array controllers, they make it so easy to modify things later on if needed that there's really not much benefit, so I started doing it on the controller when the P400's were out.

I didn't much like the interface on the older SA 5i/6i models, and definitely didn't like the even older models. They all worked great at the time, but they're so much better now.

[Gwendling]

Tank's Waaronb for the answer and the explanation.

Gerard