From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hannes Reinecke <hare@suse.de>
Subject: Re: IBM DS4300
Date: Thu, 01 Jun 2006 10:55:32 +0200
Message-ID: <447EAB84.9070404@suse.de>
References: <OFB2DC3C68.165CC670-ONC1257180.002CC9D2-C1257180.002D51F4@de.ibm.com>
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Holger Smolinski wrote:
> Gil,
>=20
> DS4300 has two modes:
>=20
> AVT, which means only one path can be used at any point in time. Using =
an
> alternate path will cause Automated Volume Transfer and add significant
> latency.
> RDAC, which means only one path can be used at any point in time. Using=
 an
> alternate path will cause an I/O error unless the volume has been migra=
ted
> manually or by a hardware_handler.
>=20
And you _really_ will want to use AVT. RDAC mode is currently _not_
supported by multipath-tools.
For AVT mode you should use the pp_tpc prioritizer.

Cheers,

Hannes
--=20
Dr. Hannes Reinecke			hare@suse.de
SuSE Linux Products GmbH		S390 & zSeries
Maxfeldstra=DFe 5				+49 911 74053 688
90409 N=FCrnberg				http://www.suse.de