[CentOS] LSI Logic MegaRAID 8480 Storage controller

I have LSI Logic MegaRAID 8480 Storage controller

I am having trouble reconfigure one of the hardware raid devices

It is configured with 4 hardware raid logical volumes on

/dev/sda
/dev/sdb
/dev/sdc
/dev/sdd.

I am in the middle of rebuilding the system,
 and at this point I am only using one of the volumes, /dev/sda

/dev/sda, /dev/sdb, and /dev/sdd are all 2 drive raid1 mirrors
I will be using the hardware raid logical volumes /dev/sdb and /dev/sdd
with their current configurations

I doubt that the hardware raid device on /dev/hda is causing
any problems

/dev/sda has two partitiions
/dev/sda1 is a 100 MB ext3 partition mounted on /boot
/dev/sda2 is a 20 GB lvm logical volume in a 67 GB volume group with
an ext3 partition mounted on /
the rest of the volume group is empty.

I don't like the /dev/sdc is configued.  It's configured as a 4 drive raid6.
It will be used for database journal, nearly all sequential writes.
I would rather use raid10

There are 3 ways to configure the hardware raid.

The is something called WebBIOS which is sort of like a web browser that
you access from the BIOS.  This is ruled out since we will need to
maintain the raid configuration with shutting down the operating system,
or applications.

There is a MegaCLI command line interface that runs under the operating
system.  Normally I prefer command line tools.  But this software is big,
and complex.  All I have been able to find is a reference manual,
that has lots of typos and is not very well organized for me to learn
what I need to know.  I have not been able to find a tutorial for this
software.  It will take more time than I have at the moment to figure
out this tool.

Finally there is the MegaRAID Storage Manager a GUI tool that
runs under the OS.  I'm running v2.77-00

So the first thing I need to do is delete the unwanted raid6 logical volume.

When I try to delete it, it refuses and says:

   This is an OS drive.  The virtual drive cannot be deleted.

Any ideas on how to get past this problem with the MegaRAID Storage Manager,

or pointers the better documentation, and maybe even a tutorial for the MegaCLI
interface.

--
Drew Einhorn