Multipath problem with PowerVault MD3200i + Oracle Enterprise Linux (5.7)

Hello,

I'm trying to configure multipath on a host (running Oracle Enterprise Linux Server 5.7) connected to a Powervault MD3200i. I'm having some unexpected problems with a missing /dev/dm-0 after rebooting.

I have configured 3 virtual disks (RAID 1) with multipath. 3 devices were created (/dev/dm-0, /dev/dm-1 and /dev/dm-2).  If I mount them manually they work fine, so I added them to fstab. After a reboot I verified that /dev/dm-1 and /dev/dm-2 were automounted but /dev/dm-0 wasn't. In fact the /dev/dm-0 disappeared from the device directory (!)

If I flush with 'multipath -F' and do 'multipath -v2' the device gets recreated but disappears on the
next reboot again. How can I solve this behaviour ? Can anyone help?

Thanks in advance.

Cheers