ADSM-L

Re: 2 Media Changer

2005-05-12 13:53:03
Subject: Re: 2 Media Changer
From: Sung Y Lee <sunglee AT US.IBM DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Thu, 12 May 2005 13:50:20 -0400
Assuming that configured correctly, I can think of 2, maybe 3rd reasons why
you would see smc0 and smc1 from the OS.

1)3584 library is partitioned.

One can check by issuing for AIX.
tapeutil -f /dev/smc0 elementinfo
tapeutil -f /dev/smc1 elementinfo

If command returns same values, then smc0 and smc1 are pointing to the same
changer physically this one library
if command returns different values, then the library has been partitioned

2)3584 multi-path architecture without automatic control path failover
configured

If you have two partitioned library then in TSM server you can define two
media changers or two libraries.
If you have only one partiioned library regardless of multi or single path
architecture you can only define one media changer or one library.

3)SAN Zoning
>
> Will TSM automatically use the second Media Changer?
>
Yes, assuming you have 3584 with multi-path architechure, if configured
correctly, the TSM will automatically use the second media changer.
There are many configuration, right version of TSM server  which need to be
taken care of before automatic failover will work.

Here's a link to a very good redbook  titled Implementing IBM tape in UNIX
Systems that describes multi path/libraries/setup for automatic
failover/SAN zoning.

http://www.redbooks.ibm.com/abstracts/sg246502.html?Open


Sung Y. Lee

"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU> wrote on 05/12/2005
10:52:27 AM:

> I just checked one of TSM Server, it has 2 Media Changer:
>
> smc0  Available 0D-08-02 IBM 3584 Library Medium Changer (FCP)
> smc1  Available 0H-08-02 IBM 3584 Library Medium Changer (FCP)
>
> From TSM Server, it only defines one Media Changer:
> DEFINE PATH TSMSERVER LTO3584 SRCTYPE=SERVER DESTTYPE=LIBRARY
> DEVICE=/dev/smc1 ONLINE=YES
>
> My question is:
> If only define  1 Media Changer, TSM Server can't use the second Media
> Changer, then why does it need 2 Media Changer? If it define the
> second Media Changer as following:
>
> DEFINE PATH TSMSERVER LTO3584 SRCTYPE=SERVER DESTTYPE=LIBRARY
> DEVICE=/dev/smc0 ONLINE=YES
>
> Will TSM automatically use the second Media Changer?
>
> TIA

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