I just created a 6-disk RAID-10 with MegaCli, and used the following commands:
(Assuming there is only one controller in these examples, so that
-aALL can be used instead of specifying a particular controller.)
Show the physical drives attached to the controller:
MegaCli -PDList -aALL
Note the "Enclosure Device ID" and "slot number" for the drives from this list as these are the numbers you replace "E" and "S" with, respectively, in the later raid-set creation commands.
Show the existing logical drives (i.e. RAID sets):
MegaCli -LDInfo -Lall -aALL
If you have an existing RAID array which you are going to re-use disks from then you need to remove the existing logical drive which those disks are part of. The logical drive number should be obtained from the previous command. Obviously this will destroy the data on this existing RAID array if you run it:
MegaCli -CfgLdDel -L<n> -aALL
Now you have a bunch of disks which should be in the "Unconfigured(good)" state and hence are available for use in a new logical drive.
Lets create a RAID-10 set of 6-disks, which is really a span of 3 RAID-1 pairs of disks:
MegaCli -CfgSpanAdd -r10 -Array0[32:2,32:3] -Array1[32:4,32:5] -Array2[32:6,32:7] -a0
In my case the disks are disks 2 to 7 on enclosure 32. These numbers are obtained from the PDList output you got earlier. If you have 4 disks then it's just two pairs, but the "ArrayN" chunks are always pairs as the underlying RAID-1 pairs in a RAID-10 set.
Your RAID array should now show up to your OS and be available for partitioning etc from there! :)