RAID Controller Failover

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Article #522

#522

From: Steve Holly
Date: Fri, 07 Nov 2003 21:33

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I'm an IT admin starting to look at building a SAN for my company and I'm
curious if anyone out there can explain how some of the popular RAID vendors
(i.e. EMC, Chaparral, Infortrend) handle failover (resuming I/O with another
RAID controller after one has failed)? I'm mostly interested in failover on
the storage side (as opposed to the host side).

Specifically I'm interested in knowing if failover is generally accomplished
by a surviving controller taking over the failed controller's (or failed
port's) AL_PA('s) or if surviving controllers actually alias failed
controller's WWN's?

Or is this something that's generally handled at the switch level.

I'm trying to better understand how failover is accomplished transparent to
the host. Many thanks for any input regarding this.

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Subject: RAID Controller Failover
From: Steve Holly <steve@sbholly.com>
Newsgroups: comp.arch.storage,it.comp.hardware.storage,comp.sys.ibm.pc.hardware.storage
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