All,

What would be the most efficient way to move 5000+ mailboxes from ServerA to
ServerB.  Both are Exchange 5.5 and in the same site.

If there is a means to execute this via script or command line it would be
preferable, but I will take anything at this point.

Thanks in advance,
Phil

I did exactly this for 6200 mbxs last year.  Found the most reliable way was
to fire up a fast (CPU-wise) NT machine with the Exchange Administrator on
it (and a 100MBit/S connection to the Exchange servers!) and use the "MS
way".  I would select 1000 at a time and "bulk move" them to the target
server.
We had some (300 or so) larger mailboxes that were in the 300MB range so the
move took about a week to complete.  If yours are smaller they'll of course
go faster.  You can also select the whole bunch all at once but we had to
stagger the moves due to it being an external customer's mail system.

Since it is Exch Admin prog what moves the data make be sure to run it on one of
servers. Also make sure that  volume with transaction logs has enough disk
space.

--
Corrections are welcome.
Please keep all discussions in NG, so that everybody can participate.

Kirill

We actually found better throughput using a fast CPU and fast LAN connection
on an NT workstation than we did running it from the server consoles.  CPU
horsepower is a major concern when doing this volume of moves and our
servers were only 400 MHz boxes.  The NT WKS was a 1 GHz box with a switched
100Mb/s connection to the server's network segment and flew through the
moves.

Excellent point!  You're going to see a *huge* amount of  transaction log
activity.  You'll also want to run the FULL Exchange backups after the moves
to get a good copy of the new IS info and clear out the old transaction
logs.