Re: 20 drives, raid 5 with hot spare, puts two drives in hot spare

rob@xxxxxxxxx wrote on Mon, 28 Apr 2014 10:46:26 GMT:

Of course, when I added these drives to the raid set I
probably should have broken them into two sets. I forgot that
18 is the maximum number of drives you can have in a raid set.
An email on the midrange-l list last night reminded me.
But, if I had done so, would that have tied up four drives for
hot spare?

I have a techdoc about this! See
http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/TD105880

To summarize, the number of drives attached to the IOAs at parity
set creation time will determine both the quantity in the arry and
the number of hot spares.

Paired adapters (IE 5913s) do not change the behavior.

And yes, I do neet to get an update out for the new EJ0L adapters
which are capable of supporting up to 96 devices.