View source for VCenter Upgrade options for small sized vCenter deployments missing

So you've got the Migration Assistant to start and now you're half way through the migration assistant before you get this:

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File:Vmwarex-largeonly.png
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The ONLY option available to you is the "X-Large" deployment size.  This is obviously less than ideal if you only want a small one!  In my case, the issue was Postgres logs.  

1. Log into the vCenter host via SSH and go to /storage/db/vpostgres/pg_log

2. Delete anything older than 30 days

   find . -mtime +30 -exec rm {} \;

That was enough to convince the Upgrade utility that I could have a smaller one :-)