Thanks, Wanda!  I really appreciate all your information!  We are trying
to create a DR strategy, sort of...I'm not happy with the way this is
being approached, but I guess a vague, hurriedly-thrown together DR plan
is better than none at all. 

-----Original Message-----
From: Wanda Prather [mailto:wprather AT JASI DOT COM] 
Sent: Saturday, February 16, 2008 9:32 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: TSM and DS8000 copy to iSCSI

Well, he's a little off, but there are replication techologies that
work:

To "continue seamlessly on without a TSM server", you are talking about
replicating the client's LIVE data, not its backups.  Check into the
replication capabilities of the DS8000; and you are correct you can also
do that with an SVC; the advantage of the SVC is that you can replicate
between unlike hardware.

There are other ways to do it as well.  There is a software product
called Double-Take that is an excellent way of replicating data bases  &
major applications; it gives you the ability to back out logical errors,
as well as recover from a disk failure or facility disaster.


If you want to replicate backups, that's a different issue, and you will
always need a TSM server.  There are several virtual tape libraries on
the market that have replication capabilities.  You have TSM write the
backups to a VTL, the VTL sends the data to a 2nd VTL via TCP/IP.  In
case of a disaster, you bring up your TSM server at the alternate site,
which is connected to the 2nd VTL, and you can start restoring (to
....what? in a facility disaster, if you lose the DS8000, you've lost
the attached clients
as well... )   And do you really want to replicate ALL your backup
versions,
or just the live data?

First make your boss clarify what problem he's trying to solve.

If he's just worried about losing the DS8000, there are plenty of
mirroring capabilities within the box.

If he's trying to create a DR strategy, and you need recovery in 4 hours
or less, you should be using replication.

And then there are issues of how long it takes to do the replication,
which involves how much bandwidth you have and how much you are willing
to pay for it.

Over short distances, (like to another building) you can replicate data
in real time if you have fibre connectivity.  Over long distances, first
look at a product like Double-Take.

You can also replicate long distance with hardware, but it gets
complicated and expensive.  (Because you have to insure that logical
groups of data, like a data base and its journal, are replicated
together, in proper order, and that the replication is complete before
you need to use that logical construct in a DR situation.)

OTOH, if what you are trying to do is just get out of the business of
moving tapes physically to your vault, then a replicating VTL is the way
to go.

That's an oversimplified version, but it should get you pointed in the
right direction.



On 2/15/08, Nancy R. Brizuela <Brizuela AT uwyo DOT edu> wrote:
>
> All,
>
> Does TSM have the ability to make a mirror copy of a client's data in 
> a SAN environment?  For instance can it copy from, say a DS8000 to  
> iSCSI storage (both on a SAN), such that we could just disconnect the 
> client from the DS8000 and point it to the iSCSI storage.  Then, upon 
> reboot, the client would seamlessly continue on, without the need for 
> a TSM server for the recovery?
>
> My boss seems to think this is possible, but I'm thinking we would 
> need some other software besides TSM, such as SAN Volume Controller.  
> Anyone doing something like this, if so, how?
>
> Thanks!
>
> Nancy Brizuela, CPA
> Systems Programmer, Senior
> University of Wyoming
> IBM/Unix Systems Group
> Ivinson Room 238
> (307)766-2958
>