thank you. Yes.. I looked at that post yesterday night. I am not mirroring anything. I used the following redhat link and made some progress.
"lvs -a -o +stripes,devices" shows that there are 4 stripes with 2 physical devices, /dev/emcpowerb1(0), /dev/emcpowerc1(0), /dev/emcpowerb1(15868), /dev/emcpowerc1(15868). I am not sure how it got the devices with 15868, guessing some kind of mapping.
Also I can force with the command "lvextend -i1 -l+100%FREE vg/stripe1" which will write the data in single stripe causing uneven performance issues.
Now I need to figure out how 4 stripes were created with 2 physical devices.