In the Megacli useful commands with examples, it shows a lot of popular commands show you how to manulapute LSI Mega RAID, such as, finding Adapter, Logical drive, Physical drive info, as well creating RAID. Here is a particular one just for RAID10.

1. Command syntax

MegaCli -CfgLdAdd -rX [E0:S0,E1:S1,...] [WT|WB] [NORA|RA] [Direct|Cached]
        [CachedBadBBU|NoCachedBadBBU] [-szXXX [-szYYY ...]]
        [-strpszM] [-Hsp[E0:S0,...]] [-AfterLdX] | [FDE|CtrlBased]  
        [-Default| -Automatic| -None| -Maximum| -MaximumWithoutCaching]
[-Cache] [-enblPI] [-Force]-aN

2.Get adapter ID (it's 0 in the example below), Enclosure ID, Slot ID:

#MegaCli64 -PDList -aALL | egrep 'Adapter|Enclosure|Slot'
Adapter #0
Enclosure Device ID: 252
Slot Number: 0
Enclosure position: N/A
Enclosure Device ID: 252
Slot Number: 1
Enclosure position: N/A
Enclosure Device ID: 252
Slot Number: 2
Enclosure position: N/A
Enclosure Device ID: 252
Slot Number: 3
Enclosure position: N/A
Enclosure Device ID: 252
Slot Number: 4
Enclosure position: N/A
Enclosure Device ID: 252
Slot Number: 5
Enclosure position: N/A

In above example, we get

Atapter ID    --> 0
Enclosure ID --> 252
Slot Number --> 0,1,2,3,4,5

3. Double check if drive are being used for Logical Drive

This command lists all Logical Drives

MegaCli64 -LDInfo -Lall -aALL

This command lists all Logical and its Physical drive info

MegaCli64 -LdPdInfo -aALL

4. Create a RAID10 array with MegaCli

Use the Adapter ID, Enclosure ID, and Slot number that found in step 1. Suppose disk slot 2,3,4,5 are not being used.

MegaCli64 -CfgLdAdd -r10 [252:2,252:3,252:4,252:5] -a0

Note: to make RAID10, minimal 4 drives are required.

5. Show system summary

MegaCli64 -ShowSummary -aALL
                                     
System
    Operating System:  Linux version 2.6.32-504.23.4.el6.x86_64
    Driver Version: 06.803.01.00-rh1
    CLI Version: 8.07.14

Hardware
        Controller
                 ProductName       : ServeRAID M5015 SAS/SATA Controller(Bus 0, Dev 0)
                 SAS Address       : 500605b004a170a0
                 FW Package Version: 12.12.0-0098
                 Status            : Optimal
        BBU
                 BBU Type          : iBBU08
                 Status            : Healthy
        Enclosure
                 Product Id        : SGPIO           
                 Type              : SGPIO
                 Status            : OK

        PD
                Connector          : Port 0 - 3<Internal>: Slot 1
                Vendor Id          : IBM-ESXS
                Product Id         : ST9300653SS     
                State              : Online
                Disk Type          : SAS,Hard Disk Device
                Capacity           : 278.464 GB
                Power State        : Active
...