SDLC, Yes you can create a new array without causing any issues with the primary array.  The Perc 6/i can support multiple arrays, up to 64 to be precise.  You may also use different specs on the drives as the first as well, but all the drives in that array must be the same or larger. Meaning, you can have you 4 15k drives in the 1st array and then have a second array created with 10k drives, BUT all the drives in that array must be 10k or higher. Quick question, are you using Open Manage Server Administrator with the host?  If not, then you will have to down the server to access the raid controller BIOS.  If you want to install it then you still have to down the server, but it makes it where you won't have to down it in the future to perform similar tasks. Let me know if you are interested and I can post the instructions.
Running 1 ESXi 5.0 U2 host with 3 vms. (2 Server 2008 R2 and 1 Server 2003 R2) with 32 GB RAM. Our business is looking on purchasing a new software that will requiere an additional 3 virtual servers. My current setup is as follows: 4 15K 600 GB on RAID 5 (Have approx 1.7 TB) Less than 190 GB left of storage. ++++++++++++++ 2 questoins Can I buy an additional 4 Drives and size and speed and create a new array without having to recreate the 1st array?   Can I buy different type of drives (slower drives, more capacity) 1TB or 2 TB and create a new and larger array?     What I am trying to avoid is to recreate the existing array since our business operates 7 days a week and I dont think my time frame will allow me to backup existing vms, delete first array, create new array with new dirves and restore virtual servers.   Any suggestion is greatly appreciated.   SDLC
How many arrays does the Perc 6i on a Dell T610 running ESXi 5.0 support and 
can I mix drive types?