9edd1e4c_NTFS__Logical_Disk_Manager__Type_of_Container_
[Extend:] You would need space on at least four disks to extend this. Similarly to stripe with parity, each section has the ability to be extended on the same disk, or others. [Add Mirror:] You will need only two disks and you would be adding a mirror of the underlying stripe. The two disks you would need cannot be the four already being used, however. This would improve the volume's fault tolerance. [Type of Container:] 
Mirrored Stripe (not shown)
S i m p l e
S p a n n e d
S t r i p e
M i r r o r
S t r i p e w i t h p a r i t y
M i r r o r e d S t r i p e ( n o t s h o w n )
NTFS: Logical Disk Manager