Something additional on the topic:
According to IBM 3583 Guide you can configure it for dual-path. It is not
full dual-ported as 3590 drives but still gives some additional
protection. The configuration in the guide is utilizing twin-tail SCSI:
FC port from the SAN switch
---> SAN Data Gateway module in first (!) 3583
---> LVD SCSI Ultrium drive (3583 does not have FC drives) in first 3583
---> LVD SCSI Ultrium drive in second 3583
---> SDG module in second library
---> port in another SAN switch
While this is not full no-single-point-of-failure configuration it gives
some additional protection against SAN switch, FC cable or SDG module
failure. SCSI failures are not covered but would affect just part of the
library.
The new for me was that this is *supported* configuration. So I am sharing
this with you. And because module in 3583 is functionally equivalent to
stand-alone device (2108-G07) I think same should be possible for 3584
with SCSI drives and two SDGs.
Somewhat strange SCSI drives to allow little bit higher availability
compared to FC but is a fact - if the SAN switch a drive is attached to
fails drive is not accessible. In pure FC environment to implement
something like the SCSI conf we would need to over-complicate the fabric
with hubs between two switches and drive(s).
At the end this achieves only redundancy not load-balancing.
Just some thoughts.

Zlatko Krastev
IT Consultant




Please respond to "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]>
Sent by:        "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]>
To:     [EMAIL PROTECTED]
cc:

Subject:        Re: Atape driver 7.0.3.0 auto failover

The 3590 is a dual ported device.  It actually has two fiber port WWPNs.
AIX actually is talking to both ports all the time but only sends out
primary IO right now to whichever is the current primary.  What is coming
is
load balancing based on what I know.  This way the ES-1000s will have
balanced IO if both ports are connected to 2 different pathways
(ES-1000s).
Finally, there is a reason 3590 is far superior.

-----Original Message-----
From: David Longo [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, February 26, 2002 4:40 PM
To: [EMAIL PROTECTED]
Subject: Re: Atape driver 7.0.3.0 auto failover


They aren't dual ported.  I have (8) 3580 LTO drives FC-AL attached.  I
have (2) McData ES-1000 switches with 4 drives on each switch.  The
library control path is currently through DRIVE 1.  I am actually looking
for
failover of the Library (/dev/smc0), in case of failure of drive 1 or the
McData switch it's on.  I can configure a second control path (in fact I
have
done this on drive 5 and it comes up on AIX as /dev/smc1, but I am not
using it).

As I read the readme on Atape it seemed the auto failover was what would
handle this, but it says only for 3590 devices.

The library has hot swap drives, but if drive1 failed or needs to be
replaced I have some amount of downtime that I wouldn't have with the
other
drives.

David Longo

>>> [EMAIL PROTECTED] 02/26/02 04:15PM >>>
Are the 3584 drives dual ported?

-----Original Message-----
From: David Longo [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, February 26, 2002 2:09 PM
To: [EMAIL PROTECTED]
Subject: Atape driver 7.0.3.0 auto failover


I notice that the Atape driver 7.0.3.0 supports Auto failover for tape
devices on 3590 devices only, as I read it.  Anybody know when it will be
supported on 3584 library with Fibre Channel?  Or is someone using it that
way now?

David Longo


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