Hi justguessing, With the S100 controller there is not any way to extend the existing array, so you will have to create a new array with the new drives. This will be a separate drive in Windows and will require its own drive letter. ftp.dell.com/.../dell-opnmang-srvr-admin-v7.1_User&Guide_3_en-us.pdf page 238 shows the steps for creating a new virtual disk.
I have a Dell PowerEdge T110 running Windows 2008 server.  It has a RAID 0 (two mirrored drives) that are running out of space.  I purchased two new drives and would like to add these drives to the existing set.  It's my understanding that you can't add drives to a mirrored set.  Can I then add the drives as a separate mirrored set?  I am using the PERC S100 RAID controller. If I add these drives as a separate RAID set, can I extend the D: or data partition on the server.  Or Do I have to create a completely new partition. Lastly, how do I use the Dell OpenManage software to create the new RAID set.  Is there documentation that explains the creation of a RAID set using the OpenManage software.   Thanks!
Adding drives to Raid set 