This is hopefully a simple question. Right now we are deploying servers which will serve as data warehouses. I know with RAID 5 the best practice is 6 disks per RAID 5. However, our plan is to use RAID 10 (both for performance and safety). We have a total of 14 disks (16 actually, but two are being used for OS). Keeping in mind that performance is very much an issue, which is better - doing several RAID 1's? Do one large RAID 10? One large RAID 10 had been our original plan, but I want to see if anyone has any opinions I haven't thought of.
Please note: This system was designed for using RAID 1+0, so losing half of the raw storage capacity is not an issue. Sorry I hadn't mentioned that initially. The concern is more whether or not we want to use one large RAID 1+0 containing all 14 disks, or several smaller RAID 1+0's and then stripe across them using LVM. I know the best practice for higher RAID levels is to never use more than 6 disks in an array.