PERC5: Dell won't sell it with 2 disks only

[Giulio Orsero]

We are using SAS5/iR configured for RAID1; due to various reasons (no
backup-battery on SAS5/iR) we decided to switch to PERC5, but Dell won't
sell us a PE840 with a PERC5 unless we buy 3 HDs instead of the 2 we usually
use for RAID1.

I understand we could use the 3rd as an hot-spare, but we usually buy 2
PE840 at a time, both with 2 HDs, one serving as a test/backup system, so we
can already use an HD from the test system as an hot-spare.
Basically Dell would force us to buy 2HDs in excess for every purchase.

This was not an issue with PERC4, which Dell would sell with 2 HDs w/o any
problem.

Does anyone know the reason for this policy?
Did anyone manage to buy a PERC5 system with just 2 HDs?

Thanks
-- 
giulioo at pobox.com