I have a PowerEdge 2900 with a raid 10 on a PERC 5/i raid controller. there is a single logical disk in use on the array broken into two partitions, the system partition which is 12 gigs, and a data partition which is 120 gigs. I am looking for a tool which can shrink the data partition then expand the system partition. I know there are many tools which can do this, the reason for my question is to find a tool which is known to work with a PERC 5/i and my current storage configuration.
Partition managers deal with logical disks formed at the OS level, they do not deal with the raid level volumes at all. I have use Acronis and Paragon mant times to do what you require, with no issues on Perc 4 thru Perc6.
If you have a single array on the disks and the partitioning is at the file system level, then the underlying RAID controller is irrelevant, as most of these partitioning tools will run from Windows. (I.e., Don't use GParted.) There are tools like Acronis Disk Manager (make sure it is the server addition) that can resize partitions while keeping all data intact. For this convenience, you pay a premium ... Acronis is around $600. There are free methods of doing this, but NO method (no matter how much you pay for it) is risk-free, so make sure you have a backup before attempting anything. Using the free methods, you will have to first backup and delete your data partition (as they can usually only extend into Unpartitioned Space), extend C into the Unpartitioned Space, then recreate and restore data to the new, smaller data partition. You can use Dell's ExtPart (similar to Windows DiskPart but without the limitation of not working on system partitions) or you can use a Server 2008, 2008 R2, Vista, or 7 DVD to extend it.
Alternatively, you can backup and reinstall/restore on desired partition sizes ... this is the safest but least convenient.