RE: RAID halting

["Leslie Rhorer" <lrhorer@satx.rr.com>]

> > [...]  What puzzles me
> > (among other things) is why do 5 of the drives show zero reads while 5
> of
> > them show very low levels of read activity, and always the same 5
> drives?
> 
> Can you identify how these drives are connected? If I recall correctly,
> you're using port multipliers (because you have to); is there anything
> like a pattern between the activity of drives and the PMPs or PMP
> channels they're connected to?

'First think of which I thought, of course.  I can't see one.  'Three
different PMPs, with both symptoms present on all 3.  'Both Hitachi and WD
drives with both symptoms.

> To borrow your expression, PMPs have left me with a bad taste in my
> mouth.

'Definitely not my favorite solution, either.  If nothing else, the loss of
a single PMP will at a minimum take the array offline.  At worst, it may
corrupt the drives unrecoverably.  I think this less likely with a
multi-lane controller.