I'm sorry to hear that David Killingsworth has been laid off.  It was so refreshing to read someone cut through the hype and document the challenges of a Notes to Exchange migration:

-When migrating to Microsoft, keep an eye on the cost of additional hardware, the cost of SQL server licenses, and the cost of bandwidth upgrades which will be inevitable and make sure and factor in those extra costs. You won't have a server for server comparison between your existing products and Microsoft. You may be able to use virtual machines for some of your systems, but some of the systems require physical hardware and/or cannot exist on the same box as other servers.

- Single Copy Storage that Microsoft has touted for Exchange is a myth (for lack of a better word) and Microsoft Engineering is actually recommending against factoring it in as a disk saving attribute when doing capacity planning. Single Copy Storage is only valid across each Exchange Store (database) on an Exchange server, and typically, you will have several Exchange Stores on each server -- so the benefit is minimal.

- Only a certain number of mailboxes can exist on an exchange server and those mailboxes must be split amongst different Exchange Stores (databases). There is recommended limit to how many stores you put on each Exchange server. It's actually quite a bit more complicated than the Domino database model and Domino's DAOS (which is server wide).

- I can't stress enough how much more bandwidth you will need compared to a Domino infrastructure.
Those second and third bullets are Microsoft myths I have attacked for years, so it's refreshing to be validated.  The bit about the mailboxes being split amongst different Exchange Stores is something I attacked when Exchange 2000 first hit the streets -- sure, you can have multiple stores, but Microsoft gives you no tools to figure out how to assign users to particular stores and having to do so in the first place is a silly arbitrary overhead thing for Exchange admins.  And apparently for no real benefit in terms of disk or storage management.

You should go back in his archives a few postings and see how many Exchange servers were used to replace Domino servers.  Let's put it this way -- there was definitely no consolidation story here.

Link: David Killingsworth: Migrating to Exchange - One Domino Admin's tell all journey ends >

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