How does the multipath group the disks ?. What could be the reason newly added LUN adds additional path to the existing mpath devices instead of creating new mpath devices ?

Issue

• After adding New luns, new paths get added to the existing mpath devices instead of paths to a new mpath devices

Before adding New Lun :

    [root@test ~]# multipath -ll
    36005076802898138f40000000000000e dm-2 IBM,2145
    [size=30G][features=1 queue_if_no_path][hwhandler=0][rw]
    \_ round-robin 0 [prio=0][active]
    \_ 1:0:0:1   sdb   8:16  [active][undef]
    \_ round-robin 0 [prio=0][enabled]
    \_ 0:0:0:1   sda   8:0   [active][undef]
    [root@test ~]#

After adding New Lun:

    [root@gest]# multipath -ll 
    36005076802898138f40000000000000e dm-2 IBM,2145
    [size=30G]        [features=1 queue_if_no_path][hwhandler=0][rw]
    \_ round-robin 0 [prio=0][enabled]
    \_ 1:0:0:1   sdb   8:16  [active][undef]
    \_ 1:0:0:2   sdd   8:48  [active][undef]
    \_ round-robin 0 [prio=0][enabled]
    \_ 0:0:0:1   sda   8:0   [active][undef]
    \_ 0:0:0:2   sdc   8:32  [active][undef]
    [root@test]#