ADSM-L

Re: [ADSM-L] Simultaneous Write

2007-08-08 17:17:59
Subject: Re: [ADSM-L] Simultaneous Write
From: "Ritter, John M" <john.ritter AT VANDERBILT DOT EDU>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 8 Aug 2007 16:16:13 -0500
I just did this on a TSM server at 5.4.1.0 level.

It seems to work fine, but I found a couple of operational limitations.

I normally have a TAPEPOOL01 and a COPYPOOL01 storage pools that I use
for tape copies.  DISKPOOL is set to go to TAPEPOOL01.

I was going to just change the TAPEPOOL01 storage pool to use a COPY
Storage Pool:  COPYPOOL01 setting. (This is what gives you the
simultaneous copy.)  But then reading through the documentation, I
discovered that this setting overrides the LANFREE settings of the
storage agents that I use on several of my machines.  In other words, if
I changed the TAPEPOOL01 to do a simultaneous copy to the COPYPOOL01,
then my LANFREE would be disabled, and the data would be sent over the
network and copied simultaneously to a TAPOOL01 tape and a COPYPOOL01
tape.  This is a real bummer, since we wanted to avoid the network
traffic to begin with by using LANFREE.

What I ended up doing was creating a TAPEPOOL02 storage pool that was
set up with a COPY Storage Pool:  COPYPOOL01 setting.  (Remember, that
this is in effect a "permanent" or global setting for the storage pool.
It really isn't intended to be turned on and off.)  I then set up a
management class that I called tapepool02backup and did individual
include statements of the filesystems I wanted to perform a simultaneous
backup on.  Here is an example of one of my lines in my
include_exclude.list file:

include         /tp02bkup/.../* tapepool02backup


In my particular case, I have EMC BCV disks that I swing over to the TSM
server machine and mount the appropriate filesystems onto the TSM
server.
Then the backup is made to the locally attached (via fiber) tape
library.  No network or LANFREE is involved.  Right now only one backup
is going to the TAPEPOOL02 storage pool.

I had hoped that I could have simply modified my normally used
TAPEPOOL01 pool to use simultaneous copy to the COPYPOOL01, but I
discovered from the documentation (and confirmed with IBM support), that
would have killed my LANFREE backups.  This approach seemed to be the
simplest alternative that I could come up with, and IBM support did not
have anything easier to suggest.

I had thought about creating an administrative script that would modify
the TAPEPOOL01 to add the COPY Storage Pool parameter, perform the
backup, and then delete the parameter.  The problem with that approach
in my case would be that during the time that the backup was being
performed, any LANFREE backups would be forced over the network and then
to the TAPEPOOL01.  I could not just delete the parameter right after I
started the simultaneous copy backup, because there would be no
guarantee that a second pair of tapes would be needed, and that would
not get the benefit of the simultaneous copy to the COPYPOOL01 tape for
the second tape involved.

If anybody else has a better approach to this problem, I sure would like
to hear it.  It would have been nice if the LANFREE storage agents would
support simultaneous copy via the Storage Agent locally attached tape
drives, but I don't know if IBM has any plans to do this in the future.

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Ribeiro, Ricardo
Sent: Wednesday, August 08, 2007 3:44 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Simultaneous Write

Hello,
I would like to know if someone has experience using the "Simultaneous
Write" feature of TSM 5.4?
We are thinking about creating a copy_pool on a remote site tape library
and enable this feature to see if we can create the copy tapes at a
remote site directly.
Has anybody done this?
Thanks!
 
Ricardo Ribeiro
Sr. Storage Administrator 
Charles Schwab & Co., Inc
Phone 602-977-4629
Cell     623-217-4139
Pager  877-478-7623
 

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