Hi Everyone,

I have deleted the thread of this email since I am sure everyone has
read a couple of times already.  I figure I would throw my $0.02 into
the mix as well.  I have done a few configs like this over the years so
I have some experience in this area.  I think you have been getting some
good feedback here and when it all said and done you should be able to
boil this down to something very workable.  So here is what I would propose.

Client A non-crit -> TSM B non-crit Pri-pool -> TSM B non-crit Copypool
-> Ship tapes to TSM C

(Optional)   |-> TSM B non-crit onsite Copypool
Client A crit -> TSM B crit Pri-pool -> TSM B crit Copypool (Virtual
Volumes on TSM C)
                                            (Optional)   |-> TSM B crit
onsite Copypool

Mirror the config for client B

I am assuming that C will be your DR site and therefore that is where
your Copy pool data should wind up.  It is not a good idea to keep both
the primary and the copy (if you are having only one copypool copy) on
the same site.  Keep in mind that if you loose site A, site B could
still be missing some critical data, i.e. Archive data that was deleted
from the owner's system and inactive versions would all be missing!  So
it is important that at least one copypool's data be separated from the
primary pool.  I am recommending that you use Virtual Volumes for the
most critical machine's copypool.  This can be done by setting up a
separate storage pool hierarchy for these critical machines of course
this is predicated on having the necessary bandwidth to transfer all the
critical data to site C.  Keep in mind to make this functional you
should also be backing up TSM A's and TSM B's DB through Virtual Volumes
to TSM C as well.

Now one thing to remember, backup environments are like buying
insurance, so the more protection you want the more expensive it will
get.  However, you must make sure that you spend enough to protect your
self!  Having said that there is a few other things you can consider.

You might consider keeping an onsite and an offsite copypool.  This
would allow for much faster recovery of data in the event of a primary
tape failure.  You will have a time delay exposure if the tape that
fails is non-crit primary you will have to retrieve the copypool tape
from offsite.  If it is a critical primary tape then you will have to
move the data back through the pipe and this could have some impact
based on what else is trying to go through the pipe at that time.

You might consider having clones of TSM A and TSM B at site C.  This
would allow for much quicker DR recovery times if that is a concern.
And to take this one step further you could even to DB restores to those
machines on a regular basis if needed.  By the way those clone instances
could run on the same system as TSM C.  That would save licensing costs
as well as have some performance advantages during DR restores.

Make sure that you plan on testing this environment.  Backing up is fine
but restores is what it is all about!  That means you must build into
the plan up front how you are going to do your testing without impacting
production and still feel confident that you can restore to production
if necessary.  This is the most common failure point for projects like
this.  They get designed and implemented with no fore thought on how to
test it and when it comes time to do the DR test they got themselves in
a jam.  There is a lot more to consider for the testing phase them what
information we have been given.

As I said before I have done a few setups that were similar to this so
if you have any further questions please feel free to ask.

Good Luck.


--
Regards,
Mark D. Rodriguez
President MDR Consulting, Inc.

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