I know this has been discussed before, but I'm interested in in current
belief/discussions regarding this, out of context of someone's =
immediate
problem.

The whole question of whether or not to use RAID 5 for your database, =
logs,
and disk pools.

Here are my current understandings of the topic:

each volume defined to adsm gets it's own thread to work with, (db, =
log,
or stg)
adsm does attempt to prioritize reads/writes within a thread to =
optimize
them as much as is possible

Assuming both of these to be true, the generic theory of life would be =
that
one should be OK to do either of two things

have multiple disks, each with one volume on them (no raid), so that =
there
are separate threads going to each spindle with no head contention.
have a single volume with a single thread, but make that thread =
really
fast (lots of disk RAIDed together).

This being said, I have had clients who have benefited from converting =
their
raid sets (with multiple volumes on the set - read - head contention on =
all
spindles) to individual volumes on sparate disks.

I have also heard from others who claim they got better performance by
switching to a raid set.  My thoughts here would be that if you're =
going to
have a raid set, that you're better off making it one big massive =
volume so
that you don't have head contention.  This of course comes at the cost =
of
only having one thread.  Has anyone found a line where having multiple
threads going to the single raid set would offset the head contention =
enough
to make it worthwhile?

What does everyone think about the different configs?

Paul