Which RAID controller do you have?  What is your existing RAID configuration?

HI JFKMD,

If you need to do any configuration or changing RAID arrays within Windows, you can use Open Manage Server Administrator.

ftp://ftp.dell.com/Manuals/all-products/esuprt_software/esuprt_ent_sys_mgmt/esuprt_ent_sys_mgmt_opnmng_svr_admin/dell-opnmang-srvr-admin-v7.4_User%27s%20Guide5_en-us.pdf

You can access the RAID utility during startup, usually it's Ctrl-R when prompted, but that depends on what RAID controller you are using.

PERC710P

RAID 5

Like to add additional hard drive arrays

The Server Admin program under Windows 2012 Server shows the logical drives (C, D, E, ...) but not the physical drives attached to the PERC710P controller.  I am looking for a utility that shows the RAID controller functions, allows one to view and change the RAID controller settings, add and remove drives from the array while the system is on line.  Isn't that the reason for using hot swap drives and redundant RAID arrays? 

Also, am I correct to believe that you can have an array of SAS drives and another array of SATA drives plugged into the same controller?

You can access the RAID utility using the CTRL-R prompt.

You can also do some RAID maintenance from within the OS, but you have to use the OpenManage Server Administrator application:

http://www.dell.com/support/home/us/en/04/Drivers/DriversDetails?driverId=V1JDD&fileId=3365593125&osCode=MWS80&productCode=poweredge-t620&languageCode=EN&categoryId=SM

You can configure new arrays with new disks, you can add disks to grow your RAID 5, etc.

Is this an add on software I need to download and install or is it already installed on my server?

Hi JFKMD,

You can download Open Manage Server Administrator (OMSA) as shared by theflash1932.

You will be able to see all functionality of the PERC BIOS in the software.

You can create array RAID within OS.

Physical drive can only be view by the controller, either OMSA or Ctrl-R

OpenManage Server Administrator (OMSA) is not the same as Windows' Server Manager.  It isn't usually preinstalled and is only installed with Windows if you use Dell's deployment tools and select its installation during deployment of Windows.  You can download it from Dell, using the link I provided earlier.  Download and run it to extract the files, then run C:\Openmanage\windows\setup.exe.  Add yourservernameoripaddress:1311 to IE's Intranet zone.

OMSA can add drives to expand the size of some RAID arrays (NOT 'nested' arrays like RAID 10/50/60, and not 'sliced' arrays where multiple VD's are configured across a single set of disks).  You can also reconfigure RAID arrays from a 2-disk RAID 1 to 3-disk RAID 5, RAID 5 to RAID 6, etc. OMSA CANNOT remove disks from any array.

Isn't that the reason for using hot swap drives and redundant RAID arrays?

No, those are features of this specific controller.  The reasons for [redundant] RAID arrays is to increase data and service availability.

Also, am I correct to believe that you can have an array of SAS drives and another array of SATA drives plugged into the same controller?

Yes, you can have both SAS and SATA on the controller/backplane, but you cannot mix them in a RAID array.