Unpartitioned space on RAID5, performance?

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I currently have a 3 drive RAID 5 on a PERC 4/SC controller.

I will be expanding it to a 5 drive RAID 5.

As a result, there will be unpartitioned space on the array. This free space will presumably spread across all 5 drives in the array?

If I don't partition this space, will I still get the benefit of those extra spindles, in terms of IOPs and lower random access times?
Since the drives are part of the array I expect there will be, but confirmation would be nice.

There are risks involved with partitioning, which I do not need to face right now. Speed is more important than storage space.

Thanks, Yama



I figured this would be a better place to put this topic, rather than the Servers and Enterprise Solutions forum, don't prove me wrong ;)
 
Extending the array will result in your current data being spread evenly across all five so you will get the benefit of higher transfer rates etc.
 
Exactly what I wanted to hear :)

Follow up question;

Is it safer to resize a partition on an array, or just to create a whole new one?
At the moment I have 'D' and 'E' on the array, shall I add an 'F' for the remaining space, or bloat up D and E equally?
 
Adding an 'F' is the safest option. Partitions need to be contiguous bits of disk so resizing both D & E will mean moving one of them (probably E) to make room to extend the other. Extending just E is reasonably safe though, it just depends how you want/need to use the space.
 
The space isn't very important at all, just need more IOPs and throughput for a minimal cost really.

I've found a product by EASEUS which supports the PERC4/SC which would let me resize it, I think I'll buy that once the array has rebuilt.

Thanks for your help!
 
You don't even need to create a new partition to use the new space, If you're using Windows you can just run Diskpart and extend the partition to fill it up. Very quick and easy.
 
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