I am not going to tell you which way to do it.  But, basically, I would
think you would want to use TSM buffers before Veritas FS caching, so I
would go with raw if it will work.  It also gets into mirroring your log and
database will be faster depending on your disk solution.

If you were using a high function disk subsystem with cache that has
mirrored disk or Raid-5 disk in it and you are comfortable that these do not
fail from a hardware error then you can avoid mirroring your data
altogether.  We use Shark.

If you are using raw D1000 or A5000 disk, then you should spread the DB and
Log across the disk.

In no case should you put the log and DB in the same file system or on the
same raw disk.  I would recommend even avoiding them on the same physical
disk in a high function disk subsystem if you can.