-----Original Message-----
From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
owner@vger.kernel.org] On Behalf Of Tim Bock
Sent: Monday, January 11, 2010 12:01 PM
To: linux-raid@vger.kernel.org
Subject: raid failure question

Hello,

Excluding the obvious multi-disk or bus failures, can anyone describe
what type of disk failure a raid cannot detect/recover from?

I have had two disk failures over the last three months, and in spite of
having a hot spare, manual intervention was required each time to make
the raid usable again.  I'm just not sure if I'm not setting something
up right, or if there is some other issue.

	I think you are trying to ask two different questions, here.  The
first concerns errors which make an array unrecoverable without intervention
by an admin.  The second concerns not promoting a hot standby whenever a
drive is failed by the array, even though the array itself is automatically
recoverable.