spreading partitions over multiple drives

[Geert Hendrickx]

> Memory is cheap, I payed the other day something like < 100 Euro for 
> 512Mb. I chose to use more memory versus buying faster processors. Next 
> thing I would do is increase the number of spindels (aka disks), 
> especially on the boxes that have losts of access from different clients 
> for very different things.

Instead of working out optimal partition layouts across the drives, I
could also just use a Vinum RAID of course.  

I wouldn't opt for a RAID-0 configuration, as it seems too stupid to
lose the entire contents of *two* disks when *one* of them fails.  

How does a RAID-1 compare to having only one disk, performancewise?
When will Vinum use parallel reads?  When one process is reading big
chunks, or only when two or more processes are reading concurrently?  Or
is the Vinum RAID-1 algorithm not optimized for performance at all?  

Any thoughts/experiences on this?  

GH