RE: Tape drive configuration suggestions -- MIDRANGE-L

Evan,

Comments inline:

> 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.

(1) Parallel saves?  Your description of the client below as being
entranced with advanced features which they may not choose to afford
strikes me as appropriate here.  If they are truly moving towards an
off-site replication environment, then their backup strategy should
support that.  They will have the opportunity to disconnect replication,
save the data files from the backup box, and then resume replication.
While they shouldn't dawdle, I'm not sure that parallel saves would be
appropriate in that environment.

Has your customer received an estimate for implementing High
Availability?  Do they know that they're looking at a large consulting
budget for implementation and licensing?  Do they know that their backup
box may end up being larger than their production box because it will
need to support a production load as well as supporting development and
testing?  How about the bandwidth costs to connect the two machines for
real-time replication between remote sites?  It's a huge thing and they
really cannot design a backup strategy until they make a commitment on
the replication thing.  If they decide not to go with replication and
still want to approach 24/7, then most steps to lessen the backup window
can be justified, including having multiple tape drives for parallel
saves.  Depending on the size of your machines, it is possible that your
machine(s) will not present data to the tape drives fast enough to push
them to their rated throughput.  If this is the case, then the benefits
of parallel saves could be marginal.

> 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

The automated, unattended backup is possible with a wide selection of
tape drives/libraries at a wide variety of costs.  As you move upwards
from 500 GB you may exceed the capacities of the 3570 and 3590
autoloader models and might need to move towards a library device using
those technologies.  The 3580 models will handle quite a bit more, but
you sacrifice some speed on the save and a lot of speed on the restore
of individual objects.

The use of 'near-line storage' can be accomplished using the BRMS/TSM
software which they already have installed.  Another alternative to
using a tape library is to set up a compressed secondary ASP using
high-capacity drives.

> 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.

It sounds like they need to make a continuum.  At one end would be a
nightly save with standard drive (large backup window).  At the other
end would be a full replication environment.  Then plot some of the
points in between.  Faster drives, parallel saves, etc.  Then start
putting some dollars at these various points and see where they blink.
Is it worth a $300,000 differential for 24x7 (I made up the dollar
figure but it strikes me as conservative).

> 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.

You have my sympathy.  On the upside, it sounds like steady work.
Hopefully you won't get in the difficult position of getting hired to
accomplish the impossible based upon someone else's bad consulting.

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

It's my understanding that a fibre channel card cannot be installed on a
720.  I went back to some documentation to confirm that and could not
find it clearly stated.  I believe it to be true but I would confirm
elsewhere.

Regards,
Andy Nolen-Parkhouse