That's is ASM right ?
If the ASM sees the new disk, it is fine. ASM is like a volumegroup/filesystem for oracle databases, if you can add it and see it after, the disk is fine.
From this perspective, looks like someone already did the initial setup for new disk, since you see it, and it has a defined name (HDS... not default one) present probably from Hitachi storage by name
What bothers me is using /dev/raw devices, it is depriciated, since Oracle ASM will use O_DIRECT flag whatever device you give to him for years now.
It will (and does) work with this setup.
You might just want to check
raw -qa to check if bindings are to /dev/mapper devices (they should be).
If not, you might want to fix that, since if you lose one path, there is a chance that database will not be able to access the disk resulting in pain and misery probably
Hope that clears things out
Regards
Peasant.