Migration to an Office 365 target environment is slower than to a local Exchange server.
Slow migration rates to Office 365 typically have two primary causes:
1. Migration to Office 365 uses the Internet to transport data, which is typically slower and less reliable than the local high-performance network cables that are used for migration to on-premise Exchange servers.
2. Microsoft implements new throttling for Office 365, which takes effect when any account (including migration admin accounts) initiate more than two concurrent data streams. This limit dramatically impacts performance when using more than 2 or 3 parallel migration threads, whereas Quest's migration applications would otherwise typically use 8 to 12 concurrent threads for standard migration machines, and even more threads for higher-end hardware.
These performance issues are independent of Quest's migration software and therefore, to some extent, are inherent with a migration to Office 365. However, Quest can offer a few suggestions to help mitigate the impact of throttling:
1. Applies to Notes Migrator for Exchange, GroupWise Migrator for Exchange and Migrator for Cloud Email.
Use multiple migration machines (more than would typically be required for an on-premises migration) running in parallel, and define a separate migration admin account for each migration machine.
2. Applies to Notes Migrator for Exchange, GroupWise Migrator for Exchange and Migrator for Cloud Email.
Set the migration thread count to 2 or 3 per migration computer.
3. Applies to Groupwise MIgrator for Exchange only
Use the "retry" features to minimize timeouts when data transmissions encounter network delays. In the GME 3.7 Program Parameters Reference, see the entries for: