You should be able to use migratepv to do this.  map your luns to the server from the clarion, cfgmgr to see the luns, add the hdisks to that VG then do your migratepv from the old luns to the new luns.  Do this 1 VG at a time, I just did this last month as a mater of fact.  From one IBM DS system to another, no problems doing it while under 60% load.  Copy and paste below of my notes.


Volume Group Migration Process
1.   Identify the hdisk(s) in the volume group you want to migrate.
a.   Use command lspv and make note of the hdisk number(s) in the volume group you want to migrate.
2.   Identify the logical volumes on each hdisk and make note of the mount points.
a.   lspv –l hdiskX
3.   Determine how much disk space the new volume group will need to contain to move existing hdisk(s) to it.
a.   df –m and add all MB blocks of mount points you made note of earlier.
4.   Create your LUN in Storage Manager and assign it to the server.
5.   cfgmgr to detect the new LUN on the server.
6.   chdev –l hdisk<n> -a pv=yes to classify the drive as a physical volume.
7.   Add that new physical volume into your existing volume group.
a.   extendvg –f vgname hdiskX
8.   Migrate old physical volumes(s) to new physical volumes.
a.   migratepv oldpv newpv
9.   Check to make sure everything has moved to new physical volume and old physical volume is empty.
a.   lspv –l hdiskX for all physical volumes affected.
10.   Remove old physical volume(s) from volume group.
a.   reducevg volumegroup hdiskX
11.   Remove old physical volume from AIX
a.   rmdev –l hdiskX –d
12.   Remove LUN from SAN with Storage Manager