How to mount a volume read-only

Hi, 

I need to edit the main.cf file to mount a volume read-only.

the path is "/mnta2/bmp", I have this in the /etc/VRTSvcs/conf/config/main.cf file: 

group mnta2_DG (
    SystemList = { emmsrv1 = 0, emmsrv2 = 1, emmsrv3 = 2, emmsrv4 = 3 }
    AutoFailOver = 0
    Parallel = 1
    AutoStartList = { emmsrv1, emmsrv2, emmsrv3, emmsrv4 }
    )

    CFSMount cfsmount3 (
        Critical = 0
        MountPoint = "/mnta2/bmp"
        BlockDevice = "/dev/vx/dsk/mnta2dg/shared_volume"
        MountOpt @emmsrv1 = "cluster"
        MountOpt @emmsrv2 = "cluster"
        MountOpt @emmsrv3 = "cluster"
        MountOpt @emmsrv4 = "cluster"
        NodeList = { emmsrv1, emmsrv2, emmsrv3, emmsrv4 }
        )

    CVMVolDg cvmvoldg3 (
        Critical = 0
        CVMDiskGroup = mnta2dg
        CVMVolume = { shared_volume }
        CVMActivation @emmsrv1 = sw
        CVMActivation @emmsrv2 = sw
        CVMActivation @emmsrv3 = sw
        CVMActivation @emmsrv4 = sw
        )

    requires group cvm online local firm
    cfsmount3 requires cvmvoldg3

    // resource dependency tree
    //
    //    group mnta2_DG
    //    {
    //    CFSMount cfsmount3
    //        {
    //        CVMVolDg cvmvoldg3
    //        }
    //    }

Does anyone know how to edit main.cf file to mount read-only?