I have a Dell PowerEdge R530 with PERC H730 RAID controller which contains 8 physical 1.88TB 7200RPM SATA drives. I asked Dell to preload it with RAID10, which they did.
My expectation of RAID 10 with my physical capacity would manifest with 14.4 TB of physical storage, but with 7.2 usable and one equally large logical volume using that space. IE RAID 10 is two nested RAID 1's each sub array with 4 physical drives total, inside a larger RAID 0 spanning the two pairs of logical RAID 1 drives all together.
So what I actually see in the pre configured Dell RAID 10 are 5 virtual disks. 4 Virtual disks are 1.8TB and the 5th is a 77GB. So two questions...
1. Are Dell "Virtual" drives the same as RAID logical drives, IE the 4 nested RAID 1 A,B,C and D drives spanned RAID 0? If so, I am guessing there is no way to present these 4 drives as 1 larger 8 TB logical drive like you would be able to with RAID 5?
2. Also, what is the purpose of the 5th 77GB virtual drive?
Thanks for the info.
doing some maths it seems it is right what you requested:
4 virtual drives * 1,8TB = 7,2 TB
which is right what you expected to have.
The fifth drive (77 GB) must be just spare space left from Raid.
You may want to contact Dell to confirm this though, just to be sure.
Meanwhile here is some info: http://www.dell.com/support/article/it/it/itbsdt1/SLN111362/en