[CentOS] IBM Storwize V3700 storage - device names

Hello,

I have IBM Storwize V3700 storage, connected to 2 IBM x3550 M4 servers 
via fiber channel. The servers are with QLogic ISP2532-based 8Gb Fibre 
Channel to
PCI Express HBA cards and run Centos 5.10

When I export a volume to the servers, each of them sees the volume 
twice, i.e  /dev/sdb and /dev/sdc, with the same size.

Previously I have installed many systems with IBM DS3500 series of 
storage and the servers see one disk per export. I am using the MPP 
drives from this package: 
http://support.netapp.com/NOW/public/apbu/oemcp/apbu_lic.cgi/public/apbu/oemcp/09.03.0C05.0652/rdac-LINUX-09.03.0C05.0652-source.tar.gz

I came upon the IBM site, saying to configure multipath (I never did it 
for DS3500 series). When I did, a new device came, /dev/dm-7, but my 
goal is to have one /dev/sdX type of device and no device mapper. I read 
that Storwize support DMP RDAC, and DS support MPP RDAC, but does anyone 
else have experience with such setup and can give an advice/hint?

Thanks in advance.