RE: Tape drive configuration suggestions

Thanks for replying Andy

You mention that ". . . the 3584 was recommended but then seen as a
>likely bottleneck."  In what way could this be seen as a bottleneck?
>Appropriately configured, it would have significant capacity in excess
>of your 500 GB.  It could attach to both machines and function
>independently on either.  I would have thought a 3584 would be almost
>the high end for your configuration, unless you need super-speedy
>restore of individual objects.

As I understand it the problem was more in the area of attaching to perform
parallel saves. There was some discussion about whether the AS/400 could
drive the 3584 at full capacity or not, but I am repeating the customers
understanding of what they were told.

I should have mentioned that the machines are geographically separate -
this was part of the reason why I felt a smaller tape drive on the
production box was appropriate, given that the intention was to replicate
and use the DR box to back up. The use of two tape drives allowed the
physical transport and swapping of data to large to send over the network.


>For less than the cost of a 3584 you could get two 3581's with 1,400 GB
>of storage at standard 2:1 compression.  Since your customer already has
>BRMS and TSM, it is possible that they would have the sophistication and
>technical expertise to take full advantage of a full-blown library
>device like the 3584.  The price difference between a 3580 (single slot)
>and a 3581 (seven slots) is not great enough to consider the 3580.
>Something like $5,000+ vs. about $8,000.

The customer probably doesn't have the sophistication - that's where we
help out, but having said that, we are in the odd position of the customer
wanting to negotiate with IBM for their solution and then have us make it
work.... By the sound of it, they may need to ask about the 3581 (and I
might need to do some more research).

>What functionality (based on business need) does you customer require
>that necessitates a full tape library as opposed to a seven-slot
>autoloader?

The functions the customer is looking to obtain is primarily automated
backup with as little tape intervention as possible, sufficient tape
capacity to back their system up in one hit without intervention, and it
seems they want some ability to access offline tape data (a somewhat naive
requirement in my view). I am trying to steer them towards a tape solution
that provides

>How price-sensitive is your customer?  Is IBM overselling?

IBM is probably unintentionally overselling - the customer has a bit of a
habit of acting and sounding like a rolls royce driver then gasping when
they see the cost. Having said that, the IBM people have  not though enough
about what the customer wants - the customer owns the box but does not
manage it (in actual fact they can't); IBM knows this but quotes based on
what the customer thinks they want. The customer bases what they think they
want on their experience with PC's. I think you know where this ends up going.

>If your customer starts looking at the 3590 models, consider a
>fiber-channel interface.  This won't fly on the 720, but it would ensure
>that the connection between the machines is not a limiting factor in
>throughput.

Minimum downtime is a requirement in the customers mind. They think they
need 24X7 and they are trying to obtain equipment that supports this.
Unfortunately they don't seem to quite get that real 24X7 also involves
designing the applications and procedures to deliver it - it's not just a
technical tape save issue. One of their consultants even had the gall to
suggest dropping the backups to improve availability (!) but I'm getting
slightly off-track.

Naturally the customer wants the device to "fly" or at the very least to be
driven to maximum capacity by their AS/400. This may involve adding extra
output cards on the AS/400 I guess but I haven't delved too deeply into it.

Do I understand what you are saying as the fiber channel would fly on the
820 but not the 720 ?

>I tend towards lowest-cost solutions, unless there is an overriding
>business requirement.

Me too.  Thanks again.

>Regards,
>Andy Nolen-Parkhouse