This is part of the NServiceBus Upgrade Guide from Version 6 to 7, which also includes the following individual upgrade guides for specific components:
Transports
- Migrating MSMQ subscription messages
- Azure Service Bus Transport (Legacy) Upgrade Version 7 to 8
- RabbitMQ Transport Upgrade Version 4 to 5
- SQL Server Transport Upgrade Version 3 to 4
Persistence
Hosting
Other
New Default Settings Values
NumberOfIOThreads now defaults to 1 thread instead of 5