That's what I was told today during our ASM training (or what I assumed base on information i got). For Oracle, IO fencing requires at least one voting disk and this is what's configured with CRS (voting disks). In non-RAC setup, you don't specify voting disks, thus, no IO fencing. Right? From my point of view, IO fencing is only needed to support split brain resolution for clustered setup and to evict nodes (anything I missed?).
Today, I did a test - I created a second ASM instance on the same host and databases were not able to register with this instance unless I register this new ASM instance with CRS (and consequently CSS is aware). There was some problem with CRS bahving strangely but this is anothe story.
In the end, I won't tell you "yes, I am 100% sure" unless I trace the processes involved. I am positive that this is the case and I actually can try to trace it down (if I have enough spare time).
>>> >>>It was quite a while since this thread posted but in the >>>meantime I figured out that ASM needs ocssd daemon because >>>this is the way of establishing communications between >>>database instances and ASM instance.
Alex, are you sure that is why it needs ocssd and not just for "fencing" functionality? -- http://www.freelists.org/webpage/oracle-l
-- Best regards, Alex Gorbachev