simple solution:

You have two servers and want these two servers to see the same SAN STORAGE ?

1) In the SAN STORAGE make sure you assign the logical disk to both AIX machines

2) run cfgmgr on AIX machines

3) Check the pvid id of the hdisks on both servers, it should be same
if there is no pvid then add one with the command ;chdev -l hdiskXX -a pv=yes

4) Check the path of the SAN HDISK by typing
lspath