I migrated about 2500 servers from SMS2003 to SCCM where the new Primary server and other SCCM infrastructure servers were virtual servers.
I migrated the clients by sending out a CCMsetup package from SMS in batches of 500 systems per hour. When the agents started to report initial full inventory the new Site server it needed more hardware and after upgrade of 2 more CPU’s and 2GB of extra RAM it’s running smooth and with good performance.
OS and roles:
Windows 2008 R2 x64
SQL Server 2008 x64
Site Database
Management point
Reporting point
Virtual Hardware:
4 CPU’s
8GB RAM
400GB virtual disc
SUP and Distribution points are placed on own machines.