[Info-vax] Health monitoring disk members of HW RAID controllers?

[Paul Sture]

In article <j1up7v$6o1$1 at usenet01.boi.hp.com>,
 Keith Parris <keithparris_deletethis at yahoo.com> wrote:

> As another note on comparative performance, with hardware RAID your 
> performance is limited to the performance of a single controller, 
> whereas with HBVS and HBR you can shadow and stripe across multiple 
> controllers for higher performance than any single controller can 
> provide. I also consider such an individual controller to be a potential 
> single point of failure. And because the two controllers in a 
> dual-redundant pair are intimately connected and have to coordinate with 
> each other, for the highest availability configurations I consider even 
> such a dual-redundant controller to be a potential single point of 
> failure. With HBVS you can shadow across controllers [or pairs] to avoid 
> any such potential single points of failure.

You are correct about a pair of controllers being a single point of 
failure.  I once jammed a pair by inadvertently issuing a wrong command 
to one of them (the danger of using a mouse to paste).  It took an 
engineer to fix that.  In this case shadow copies of the disks concerned 
were in a different cabinet, so we were covered, fortunately.

-- 
Paul Sture