Can not connect EMC

I have a EMC cx300 , I have installed powerpath , naviagent to the Redhat server , direct connect to the server , it works fine before .

I have reboot these two device , then found that the EMC device is not connected to the server , just found there are many devices ( emcpowera  , emcpowerb , emcpowerc ...... ) in /dev , I tried to remove these devices and reboot them , but still not work , can advise what can I do ?

brw-rw----    1 root     root     246, 126 Dec 21  2010 emcpowerhx14

brw-rw----    1 root     root     246, 127 Dec 21  2010 emcpowerhx15

brw-rw----    1 root     root     246, 114 Dec 21  2010 emcpowerhx2

brw-rw----    1 root     root     246, 115 Dec 21  2010 emcpowerhx3

brw-rw----    1 root     root     246, 116 Dec 21  2010 emcpowerhx4

brw-rw----    1 root     root     246, 117 Dec 21  2010 emcpowerhx5

Thanks .